JEE

place holder for JEE app servers.

CouchDB

Apache CouchDB, commonly referred to as CouchDB, is a free and open source document-oriented database written in the Erlang programming language. It is designed for local replication and to scale vertically along a wide range of devices.

Overview

CouchDB is most similar to other document stores like MongoDB and Lotus Notes. It is not a relational database management system. Instead of storing data in rows and columns, the database manages a collection of JSON documents. The documents in a collection need not share a schema, but retain query abilities via views. Views are defined with aggregate functions and filters are computed in parallel, much like MapReduce.

Views are generally stored in the database and their indexes updated continuously, although queries may introduce temporary views. CouchDB supports a view system using external socket servers and a JSON based protocol. As a consequence, view servers have been developed in a series of languages.

CouchDB exposes a RESTful HTTP API and a large number of pre-written clients are available. Additionally, a plugin architecture allows for using different computer languages as the view server such as JavaScript (default), PHP, Ruby, Python and Erlang. Support for other languages can be easily added.

CouchDB was accepted into Apache incubation in February 2008 and became a top level project in November 2008. Despite its low version number of 0.10, it is already in use in many software projects and web sites, including Ubuntu, where it is used to synchronize address and bookmark data.

(From http://en.wikipedia.org/wiki/CouchDB on January 09, 2010)

MySQL

MySQL is a relational database management system (RDBMS) which has more than 11 million installations. The program runs as a server providing multi-user access to a number of databases.
MySQL is owned and sponsored by a single for-profit firm, the Swedish company MySQL AB, now a subsidiary of Sun Microsystems,[3] which holds the copyright to most of the codebase. The project's source code is available under terms of the GNU General Public License, as well as under a variety of proprietary agreements.
"MySQL" is officially pronounced /maɪˌɛskjuːˈɛl/ (My S Q L), not "My sequel" /maɪˈsiːkwəl/. This adheres to the official ANSI pronunciation; SEQUEL was an earlier IBM database language, a predecessor to the SQL language. The company does not take issue with the pronunciation "My sequel" or other local variations.

History

This article or section needs to be updated. Please update the article to reflect recent events or newly available information, and remove this template when finished.
Milestones in MySQL development include:
MySQL was first released internally on 23 May 1995
Windows version was released on January 8, 1998 for Windows 95 and NT
Version 3.23: beta from June 2000, production release January 2001
Version 4.0: beta from August 2002, production release March 2003 (unions)
Version 4.1: beta from June 2004, production release October 2004 (R-trees and B-trees, subqueries, prepared statements)
Version 5.0: beta from March 2005, production release October 2005 (cursors, stored procedures, triggers, views, XA transactions)
Version 5.1: currently pre-production (since November 2005) (event scheduler, partitioning, plugin API, row-based replication, server log tables)
Sun Microsystems acquired MySQL AB on 26 February 2008.
Future releases
The MySQL 5.1 roadmap outlines support for:
Pluggable storage engine API
Partitioning
Event Scheduling
XML functions
Row-based replication
Support for parallelization is also part of the roadmap for future versions.
Support for supplementary Unicode characters, beyond the 65536 characters of the Basic Multilingual Plane (BMP) is announced for MySQL 6.0.
Foreign key support for all storage engines is targeted for release in MySQL 6.1 (although it has been present since version 3.23.44 for InnoDB).
The current MySQL 5.1 development release is 5.1.29.
A new storage engine is also in the works, called Falcon. A preview of Falcon is already available on MySQL's website.

Support and licensing
Via MySQL Enterprise MySQL AB offers support itself, including a 24/7 service with 30-minute response time, the support team has direct access to the developers as necessary to handle problems. In addition it hosts forums and mailing lists, employees and other users are often available in several IRC channels providing assistance.
Buyers of MySQL Enterprise have access to binaries and software that is certified for their particular operating system, and access to monthly binary updates with the latest bug fixes. Several levels of Enterprise membership are available, with varying response times and features ranging from how to and emergency support through server performance tuning and system architecture advice. The MySQL Network Monitoring and Advisory Service monitoring tool for database servers is available only to MySQL Enterprise customers.
MySQL Server is available as free software under the GNU General Public License (GPL), and the MySQL Enterprise subscriptions include a GPL version of the server, with a traditional proprietary version available on request at no additional cost for cases where the intended use is incompatible with the GPL.
Both the MySQL server software itself and the client libraries are distributed under a dual-licensing format. Users may choose the GPL, which MySQL has extended with a FLOSS License Exception. It allows Software licensed under other OSI-compliant Open Source licenses, which are not compatible to the GPL, to link against the MySQL client libraries.
Customers that do not wish to be bound to the terms of the GPL may choose to purchase a proprietary license.
Like many open-source programs, the name "MySQL" is trademarked and may only be used with the trademark holder's permission.
Some users have independently continued to develop earlier versions of the client libraries, which was distributed under the less-restrictive GNU Lesser General Public License (LGPL).
Issues
There has been some controversy regarding the distribution of GPL licensed MySQL library files with other open source applications. The biggest controversy arose with PHP, which has a license incompatible with the GPL. This was later resolved when MySQL created a license exception that explicitly allows the inclusion of the MySQL client library in open source projects that are licensed under a number of OSI-compliant Open Source licenses, including the PHP License.
In September 2005, MySQL AB and SCO forged a partnership for "joint certification, marketing, sales, training and business development work for a commercial version of the database for SCO's new OpenServer 6 version of Unix". SCO raised controversy beginning in 2003 with a number of high-profile lawsuits related to the Linux Operating System. Various MySQL employees expressed that the company was committed to serving its end users, regardless of their operating system choice, that the company would leave it to the courts to resolve the SCO licensing controversy, and that other common open source databases have also been ported to, and support, SCO OpenServer.
In October 2005, Oracle Corporation acquired Innobase OY, the Finnish company that developed the InnoDB storage engine that allows MySQL to provide such functionality as transactions and foreign keys. A press release by Oracle that was issued after the acquisition, mentioned that the contracts that make the company's software available to MySQL AB would be due for renewal (and presumably renegotiation) some time in 2006. During the MySQL Users Conference in April 2006, MySQL issued a press release which confirmed that MySQL and Innobase OY agreed to a multi-year extension of their licensing agreement.
In February 2006, Oracle Corporation acquired Sleepycat Software, makers of the Berkeley DB, a database engine onto which another MySQL storage engine was built.
Criticism

It has been suggested that some of the information in this article's Criticism or Controversy section(s) be merged into other sections to achieve a more neutral presentation. (Discuss)
MySQL's divergence from the SQL standard regarding the treatment of NULL values and default values has been criticized. Its handling of dates in versions prior to 5.0 allows storing a date with a day beyond the last day of a month with fewer than 31 days, and arithmetic operations are vulnerable to either integer overflow or floating point truncation. Since version 5 of the server, the treatment of illegal values varies according to use of the "SQL Mode" set in the server, which is by default set to the unusually tolerant state that critics dislike.
When the beta version of MySQL 5.0 was released in March 2005, David Axmark, a co-founder of MySQL, said that "People have been criticizing MySQL since we started for not having stored procedures, triggers and views," and "We're fixing 10 years of criticism in one release." MySQL 5.0's 13 October build 5.0.15 was released for production use on 24 October 2005, after more than two million downloads in the 5.0 beta cycle.
Critical bugs sometimes do not get fixed for long periods of time. An example is a bug with status critical existing since 2003.
MySQL shows poor performance when used for Data Warehousing; this is partly due to inability to utilize multiple CPU cores for processing a single query.
The developer of the Federated Storage Engine states that "The Federated Storage Engine is a proof-of-concept storage engine" [1], though it was included and turned on by default in the main distributions of MySQL version 5.0. Some of the short-comings are documented in the "MySQL Federated Tables: The Missing Manual".

(From http://en.wikipedia.org/wiki/Mysql on November 25, 2008)

PostgreSQL

PostgreSQL is an object-relational database management system (ORDBMS). It is released under a BSD-style license and is thus free software. As with many other open-source programs, PostgreSQL is not controlled by any single company, but relies on a global community of developers and companies to develop it.

Product name

The mixed-capitalization of the PostgreSQL name can confuse some people on first viewing. The several pronunciations of 'SQL' can lead to this confusion. PostgreSQL's developers pronounce it /poːst ɡɹɛs kjuː ɛl/; (Audio sample, 5.6k MP3). It is also common to hear it abbreviated as simply "postgres", which was its original name. Because of ubiquitous support for the SQL Standard amongst most relational databases, the community considered changing the name back to Postgres. However, the PostgreSQL Core Team announced in 2007 that the product would continue to be named PostgreSQL. The name refers to the project's origins as a "post-Ingres" database, the original authors having also developed the Ingres database.
History

PostgreSQL evolved from the Ingres project at University of California, Berkeley. In 1982, the project leader, Michael Stonebraker, left Berkeley to commercialize Ingres. He returned to Berkeley in 1985 and started a post-Ingres project to address the problems with contemporary database systems that had become increasingly clear during the early 1980s. The new project, Postgres, aimed to add the fewest features needed to completely support types. These features included the ability to define types and to fully describe relationships – something used widely before but maintained entirely by the user. In Postgres, the database "understood" relationships, and could retrieve information in related tables in a natural way using rules. Postgres used many ideas of Ingres but not its code.
Starting in 1986, the team published a number of papers describing the basis of the system, and by 1988 had a prototype version. The team released version 1 to a small number of users in June 1989, then version 2 with a re-written rules system in June 1990. Version 3, released in 1991, again re-wrote the rules system, and added support for multiple storage managers and an improved query engine. By 1993 the great number of users began to overwhelm the project with requests for support and features. After releasing version 4 — primarily a cleanup — the project ended.
But open-source developers could obtain copies and develop the system further, because Berkeley had released Postgres under the BSD license. In 1994, Berkeley graduate students Andrew Yu and Jolly Chen replaced the Ingres-based QUEL query language interpreter with one for the SQL query language, creating Postgres95. The code was released on the web.
In July 1996, Marc Fournier at Hub.Org Networking Services provided the first non-university development server for the open source development effort. Along with Bruce Momjian and Vadim B. Mikheev, work began to stabilize the code inherited from Berkeley. The first open source version was released on August 1, 1996.
In 1996, the project was renamed to PostgreSQL to reflect its support for SQL. The first PostgreSQL release formed version 6.0 in January 1997. Since then, the software was maintained by a group of database developers and volunteers around the world, coordinating via the Internet.
Although the license allowed for the commercialization of Postgres, the code did not develop commercially at first — somewhat surprisingly considering the advantages Postgres offered. The main offshoot originated when Paula Hawthorn (an original Ingres team member who moved from Ingres) and Michael Stonebraker formed Illustra Information Technologies to commercialize Postgres.
In 2000, former Red Hat investors created the company Great Bridge to commercialize PostgreSQL and compete against commercial database vendors. Great Bridge sponsored several PostgreSQL developers and donated many resources back to the community, but by late 2001 closed due to tough competition from companies like Red Hat and to poor market conditions.
In 2001, Command Prompt, Inc. released Mammoth PostgreSQL, the oldest surviving commercial PostgreSQL distribution. It continues to actively support the PostgreSQL community through developer sponsorships and projects including PL/Perl, PL/php, and hosting of community projects such as the PostgreSQL Build Farm.
In January 2005, PostgreSQL received backing by database vendor Pervasive Software, known for its Btrieve product which was ubiquitous on the Novell NetWare platform. Pervasive announced commercial support and community participation and achieved some success. But in July 2006, it left the PostgreSQL support market.
In mid-2005 two other companies announced plans to commercialize PostgreSQL with focus on separate niche markets. EnterpriseDB added functionality to allow applications written to work with Oracle to be more readily run with PostgreSQL. Greenplum contributed enhancements directed at data warehouse and business intelligence applications, including the BizGres project.
In October 2005, John Loiacono, executive vice president of software at Sun Microsystems, commented: "We're not going to OEM Microsoft but we are looking at PostgreSQL right now," although no specifics were released at that time. By November 2005, Sun had announced support for PostgreSQL. By June 2006, Sun Solaris 10 (6/06 release) shipped with PostgreSQL.
In August 2007, EnterpriseDB announced the Postgres Resource Center and EnterpriseDB Postgres, designed to be a fully configured distribution of PostgreSQL including many contrib modules and add-on components. EnterpriseDB Postgres was renamed to Postgres Plus in March 2008.
The PostgreSQL project continues to make yearly major releases and minor "bugfix" releases, all available under the BSD license, based on contributions from both commercial vendors, support companies, and open source programmers at large.

(From http://en.wikipedia.org/wiki/Postgres on November 25, 2008)

FreeBSD

History and development

FreeBSD's development began in 1993 with a quickly growing, unofficial patchkit maintained by users of the 386BSD operating system. This patchkit forked from 386BSD and grew into an operating system taken from U.C. Berkeley's 4.3BSD-Lite (Net/2) tape with many 386BSD components and code from the Free Software Foundation. The first official release was FreeBSD 1.0 in December 1993, coordinated by Jordan Hubbard, Nate Williams and Rod Grimes with a name thought up by David Greenman. Walnut Creek CDROM agreed to distribute FreeBSD on CD and gave the project a machine to work on along with a fast Internet connection, which Hubbard later said helped stir FreeBSD's rapid growth. A "highly successful" FreeBSD 1.1 release followed in May 1994.
However, there were legal concerns about the BSD Net/2 release source code used in 386BSD. After a lawsuit between UNIX copyright owner at the time Unix System Laboratories and the University of California, Berkeley, the FreeBSD project re-engineered most of the system using the 4.4BSD-Lite release from Berkeley, which, owing to this lawsuit, had none of the AT&T source code earlier BSD versions had depended upon, making it an unbootable operating system. Following much work, the outcome was released as FreeBSD 2.0 in January 1995.
FreeBSD 2.0 featured a revamp of the original Carnegie Mellon University Mach virtual memory system, which was optimized for performance under high loads. This release also introduced the FreeBSD Ports system, which made downloading, building and installing third party software very easy. By 1996 FreeBSD had become popular among commercial and ISP users, powering extremely successful sites like Walnut Creek CD-ROM (a huge repository of software that broke several throughput records on the Internet), Yahoo! and Hotmail. The last release along the 2-STABLE branch was 2.2.8 in November 1998. FreeBSD 3.0 brought many more changes, including the switch to the ELF binary format. Support for SMP systems and the 64 bit Alpha platform were also added. The 3-STABLE branch ended with 3.5.1 in June 2000.

Beastie

FreeBSD's mascot is the generic BSD daemon, also known as Beastie
For many years FreeBSD's logo was the generic BSD daemon, also called Beastie, a slurred phonetic pronunciation of BSD. First appearing in 1976 on UNIX T-shirts purchased by Bell Labs, the more popular versions of the BSD daemon were drawn by animation director John Lasseter beginning in 1984. Several FreeBSD-specific versions were later drawn by Tatsumi Hosokawa. Through the years Beastie became both beloved and criticized as perhaps inappropriate for corporate and mass market exposure. Moreover it was not unique to FreeBSD. In lithographic terms, the Lasseter graphic is not line art and often requires a screened, four colour photo offset printing process for faithful reproduction on physical surfaces such as paper. However drawn, the BSD daemon was thought to be too graphically detailed for smooth size scaling and aesthetically over dependent upon multiple colour gradations, making it hard to reliably reproduce as a simple, standardized logo in only two or three colours, much less in monochrome. Because of these worries, a competition was held and a new logo designed by Anton K. Gural, still echoing the BSD daemon, was released on October 8, 2005. Meanwhile Lasseter's much known take on the BSD daemon carries forth as official mascot of the FreeBSD Project.

Version History

FreeBSD 4
4.0-RELEASE appeared in March 2000 and the last 4-STABLE branch release was 4.11 in January 2005. FreeBSD 4 was a favorite operating system for ISPs and web provider during the first .com bubble, and is widely regarded as one of the most stable and high performance operating systems of the whole Unix lineage.
FreeBSD 5
After almost three years of development, the first 5.0-RELEASE in January 2003 was widely anticipated, featuring support for advanced multiprocessor and application threading, and for the UltraSPARC and ia64 platforms. The first 5-STABLE release was 5.3 (5.0 through 5.2.1 were cut from -CURRENT). The last release from the 5-STABLE branch was 5.5 in May 2006.
The largest architectural development in FreeBSD 5 was a major change in the low-level kernel locking mechanisms to enable better symmetric multi-processor (SMP) support. This released much of the kernel from the MP lock, which is sometimes called the Giant lock. More than one process could now execute in kernel mode at the same time. Other major changes included an M:N native threading implementation called Kernel Scheduled Entities. In principle this is similar to Scheduler Activations. Starting with FreeBSD 5.3, KSE was the default threading implementation until it was replaced with a 1:1 implementation in FreeBSD 7.0.
FreeBSD 5 also significantly changed the block I/O layer by implementing the GEOM modular disk I/O request transformation framework contributed by Poul-Henning Kamp. GEOM enables the simple creation of many kinds of functionality, such as mirroring (gmirror) and encryption (GBDE and GELI). This work was supported through sponsorship by DARPA.
The 5.4 and 5.5 releases of FreeBSD confirmed the FreeBSD 5.x branch as a highly stable and high-performing release, although it had a long development period due to the large feature set. Earlier releases on the 5.x branch are not considered stable enough for production deployment.
FreeBSD 6
FreeBSD 6.0 was released on November 4, 2005. The most recent FreeBSD 6 release was 6.4, on November 11, 2008. These versions continue work on SMP and threading optimization along with more work on advanced 802.11 functionality, TrustedBSD security event auditing, significant network stack performance enhancements, a fully preemptive kernel and support for hardware performance counters (HWPMC). The main accomplishments of these releases include removal of the Giant lock from VFS, implementation of a better-performing optional libthr library with 1:1 threading and the addition of a Basic Security Module (BSM) audit implementation called OpenBSM, which was created by the TrustedBSD Project (based on the BSM implementation found in Apple's open source Darwin) and released under a BSD-style license.
FreeBSD 7
FreeBSD 7.0 was released on 27 February 2008. The most recent FreeBSD 7 release was 7.1, on January 05, 2009. New features include SCTP, UFS journaling, an experimental port of Sun's ZFS file system, GCC4, improved support for the ARM architecture, jemalloc (a memory allocator optimized for parallel computation, which was ported to Firefox 3), and major updates and optimizations relating to network, audio, and SMP performance. Benchmarks have shown significant speed improvements over previous FreeBSD releases as well as Linux. The new ULE scheduler has seen much improvement but a decision was made to ship the 7.0 release with the older 4BSD scheduler, leaving ULE as a kernel compile-time tunable. In FreeBSD 7.1 ULE was the default for the i386 and AMD64 architectures. Starting from version 7.1 DTrace was integrated.
FreeBSD 8
As of 2008, FreeBSD 8.0 is the "bleeding edge" development version, called -CURRENT in FreeBSD development terminology. It will feature the ability for jails to have more than one IP (with support for IPv6), superpages, Xen DomU support, network stack virtualization, stack-smashing protection, removal of Giant lock from the Tty layer, much improved ZFS support and a new USB stack. FreeBSD 8.0 is planned to be released in the 3rd quarter of 2009.

(From http://en.wikipedia.org/wiki/Freebsd, April 18, 2009)

Haiku

Haiku is a free and open source operating system compatible with BeOS. Its development began in 2001, and the operating system became self-hosting in 2008, with the first alpha release in September 2009 and the second in May 2010.
Haiku is supported by Haiku, Inc., a non-profit organization based in Rochester, New York, that was founded in 2003 for that purpose.

History
Haiku began as the OpenBeOS project in 2001, the year that Be, Inc. was bought by Palm, Inc. and BeOS development was discontinued; the focus of the project was to support the BeOS user community by creating an open-source, backward-compatible replacement for BeOS. The first project by OpenBeOS was a community-created "stop-gap" update for BeOS 5.0.3 in 2002. In 2003, a non-profit organization (Haiku Inc.) was registered in Rochester, New York, to financially support development, and in 2004, after a notification of infringement upon Palm's trademark on the BeOS name was sent to OpenBeOS, the project was renamed as Haiku. However, development would only reach its first milestone in September 2009 with the release of Haiku R1/Alpha 1. This was followed in May 2010 by R1/Alpha 2, which contains more than 300 bug-fixes and improvements.

Development

Haiku is developed in C++ and provides an object-oriented API.
The modular design of BeOS allowed individual components of Haiku to initially be developed in teams in relative isolation, in many cases developing them as replacements for the BeOS components prior to the completion of other parts of the operating system. The original teams developing these components, including both servers and APIs (collectively known in Haiku as "kits"), included:
App/Interface – develops the Interface, App and Support kits.
BFS – develops the Be File System, which is mostly complete with the resulting OpenBFS.
Game – develops the Game Kit and its APIs.
Input Server – the server that handles input devices, such as keyboards and mice, and how they communicate with other parts of the system.
Kernel – develops the kernel, the core of the operating system.
Media – develops the audio server and related APIs.
MIDI – implements the MIDI protocol.
Network – writes drivers for network devices and APIs relating to networking.
OpenGL – develops OpenGL support.
Preferences – recreates the preferences suite.
Printing – works on the print servers and drivers for printers.
Screen Saver – implements screen saver functionality.
Storage – develops the storage kit and drivers for required filesystems.
Translation – recreates the reading/writing/conversion modules for the different file formats.
A few kits have been deemed feature complete and the rest are in various stages of development.
The Haiku kernel is a modular hybrid kernel and a fork of NewOS, a modular kernel written by former Be Inc. engineer Travis Geiselbrecht. Like the rest of the system it is currently still under heavy development. Many features have been implemented, including a virtual file system (VFS) layer and rudimentary symmetric multiprocessing (SMP) support.
Compatibility with BeOS

Haiku aims to be compatible with BeOS at both the source and binary level, allowing software written and compiled for BeOS to compile and run without modification on Haiku. This would provide Haiku users with an instant library of applications to choose from (even programs whose developers were no longer in business or had no interest in updating them), in addition to allowing development of other applications to resume from where they had been terminated following the demise of Be, Inc. This dedication to compatibility also has its drawbacks, though, requiring Haiku to use version 2.95 of the compiler GCC, which is 9 years old. Switching to using the newer GCC version 4 breaks compatibility with BeOS software; therefore, Haiku supports being built as a hybrid GCC4/GCC2 environment. This allows the use of both GCC version 2 and version 4 binaries at the same time.
Note that this compatibility applies to x86 systems only. The PowerPC version of BeOS R5 will not be supported. As a consequence, the ARM, 68k and PPC ports of Haiku use only the gcc4 compiler.
Despite these attempts, compatibility with a number of system add-ons that use private APIs will not be implemented. These include additional filesystem drivers and media codec add-ons, although the only affected add-ons for BeOS R5 not easily re-implemented are Indeo 5 media decoders for which no specification exists.
R5 binary applications that run successfully under Haiku (as of May 2006) include: Opera, Firefox, NetPositive, Quake II, Quake III, SeaMonkey, Vision and VLC media player.
Driver compatibility is incomplete, and unlikely to cover all kinds of BeOS drivers. 2D graphics drivers in general work exactly the same as on R5, as do network drivers. Moreover, Haiku offers a source-level FreeBSD network driver compatibility layer, which means that it can support any network hardware that will work on FreeBSD. Audio drivers using API versions prior to BeOS R5 are as-yet unsupported, and unlikely to be so; however, R5-era drivers work.
Low-level device drivers, namely for storage devices and SCSI adapters, will not be compatible. USB drivers for both the second- (BeOS 5) and third- (BeOS Dano) generation USB stacks will work, however.
In some other aspects, Haiku is already more advanced than BeOS. For example, the interface kit allows the use of a layout system to automatically place widgets in windows, while on BeOS the developer had to specify the exact position of each widget by hand. This allows for GUIs that will render correctly with any font size and makes localization of applications much easier, as a longer string in a translated language will make the widget grow, instead of being partly invisible if the widget size were fixed.
Beyond R1

Initial planning for R2 has started through the "Glass Elevator" project (a reference to the children's novel Charlie and the Great Glass Elevator). The only detail confirmed so far is that it will switch to a current GCC release (namely v4.3.3).
A compatibility layer is planned that will allow applications developed for Haiku R1 to run on Haiku R2 and later. This was mentioned in a discussion on the Haiku mailing list by one of the lead developers, Axel Dörfler. Suggested new features include file indexing on par with Unix's Beagle, Google Desktop and Mac OS X's Spotlight, greater integration of scalable vector graphics into the desktop, proper support for multiple users, and additional kits.

(From http://en.wikipedia.org/wiki/Haiku_(operating_system), May 22, 2010)

Linux

Description

From http://en.wikipedia.org/wiki/Linux:
Linux (commonly pronounced IPA: /ˈlɪnəks/ in English; variants exist[1]) is a Unix-like computer operating system family which uses the Linux kernel. Linux is one of the most prominent examples of free software and open source development; typically all the underlying source code can be freely modified, used, and redistributed by anyone.[2]
Predominantly known for its use in servers, it is installed on a wide variety of computer hardware, ranging from embedded devices and mobile phones to supercomputers.[3]
The name "Linux" comes from the Linux kernel, originally written in 1991 by Linus Torvalds. The system's utilities and libraries usually come from the GNU operating system, announced in 1983 by Richard Stallman. The GNU contribution is the basis for the alternative name GNU/Linux.[4]

Stats

NetBSD

NetBSD is a freely available open source version of the Unix-derivative Berkeley Software Distribution (BSD) computer operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design, stability and performance of the system. Due to convenient license and portability, NetBSD is often used in embedded systems.
The current stable release of NetBSD is version 5.0.2 (February 12, 2010).
Contents
1 History
2 Features
2.1 Portability
2.2 Portable build framework
2.3 The pkgsrc packages collection
2.4 Symmetric multiprocessing
2.5 Security
2.6 Virtualization
2.7 Storage
2.8 Compatibility with other operating systems
3 Licensing
4 Releases
5 Logo
6 The NetBSD Foundation
7 Examples of use
8 Hosting
9 See also
10 Notes
11 References
12 External links
History

NetBSD was originally derived from the 4.3BSD release of the Berkeley Software Distribution from the Computer Systems Research Group of the University of California, Berkeley, via their Net/2 source code release and the 386BSD project. The NetBSD project began as a result of frustration within the 386BSD developer community with the pace and direction of the operating system's development. The four founders of the NetBSD project, Chris Demetriou, Theo de Raadt, Adam Glass and Charles Hannum, felt that a more open development model would be beneficial to the project; one which was centered on portable, clean, correct code. Their aim was to produce a unified, multi-platform, production-quality, BSD-based operating system. The name "NetBSD" was suggested by de Raadt, based on the importance and growth of networks such as the Internet at that time, and the distributed, collaborative nature of its development.
The NetBSD source code repository was established on March 21, 1993 and the first official release, NetBSD 0.8, was made in April, 1993. This was derived from 386BSD 0.1 plus the version 0.2.2 unofficial patchkit, with several programs from the Net/2 release missing from 386BSD re-integrated, and various other improvements. The first multi-platform release, NetBSD 1.0, was made in October 1994. Also in 1994, for disputed reasons, one of the founders, Theo de Raadt, left the project. He later founded a new project, OpenBSD, from a forked version of NetBSD 1.0 near the end of 1995. In 1998, NetBSD 1.3 introduced the pkgsrc packages collection.
Until 2004, NetBSD 1.x releases were made at roughly annual intervals, with minor "patch" releases in between. From release 2.0 onwards, each major NetBSD release corresponds to an incremented major version number, i.e. the major releases following 2.0 are 3.0, 4.0 and so on. The previous minor releases are now divided into two categories: x.y "stable" maintenance releases and x.y.z releases containing only security and critical fixes.
Features

Portability
As the project's motto ("Of course it runs NetBSD" ) suggests, NetBSD has been ported to a large number of 32- and 64-bit architectures. These range from VAX minicomputers to Pocket PC PDAs. As of 2009, NetBSD supports 57 hardware platforms (across 15 different processor architectures). Although the Linux 2.6 kernel includes support for more processor architectures, the NetBSD distribution supports more platforms than any single Linux distribution. The kernel and userland for these platforms are all built from a central unified source-code tree managed by CVS. Currently, unlike other kernels such as μClinux, the NetBSD kernel requires the presence of an MMU in any given target architecture.
NetBSD's portability is aided by the use of hardware abstraction layer interfaces for low-level hardware access such as bus input/output or DMA. Using this portability layer, device drivers can be split into "machine-independent" and "machine-dependent" components. This allows a single driver to be easily used on several platforms by hiding details of exactly how the driver accesses the hardware, and reduces the amount of work needed to port it to a new architecture.
This enables, for instance, a driver for a specific PCI card to work whether that card is in a PCI slot on an IA-32, Alpha, PowerPC, SPARC, or other architecture with a PCI bus. Also, a single driver for a specific device can operate via several different buses, for example ISA, PCI, PC card, etcetera.
In comparison, Linux device driver code often needs to be reworked for every new architecture. As a consequence, in recent porting efforts by NetBSD and Linux developers, NetBSD has taken much less time to port to new hardware.
This platform independence aids the development of embedded systems, particularly since NetBSD 1.6, when the entire toolchain of compilers, assemblers, linkers, and other tools fully supported cross-compiling.
In 2005, as a demonstration of NetBSD's portability and suitability for embedded applications, Technologic Systems, a vendor of embedded systems hardware, designed and demonstrated a NetBSD-powered kitchen toaster.
Commercial ports to embedded platforms, including the AMD Geode LX800, Freescale PowerQUICC processors, Marvell Orion, AMCC 405 family of PowerPC processors, Intel XScale IOP and IXP series, were available from and supported by Wasabi Systems (defunct as of March, 2009).
Portable build framework
The NetBSD cross-compiling framework (also known as "build.sh" ) allows a complete NetBSD system for an architecture to be built from another system of different architecture (usually faster or with more hardware resources), even on a different operating system, since the framework supports most POSIX-compliant systems. Several embedded systems using NetBSD have required no additional software development other than toolchain and target rehost.
The pkgsrc packages collection
NetBSD features pkgsrc (short for "package source"), a framework for building and managing third-party application software packages. The pkgsrc collection consists of more than 8100 packages as of January 2009. Building and installing packages such as KDE, GNOME, the Apache HTTP server or Perl is performed through the use of a system of makefiles. This can automatically fetch the source code, unpack, patch, configure, build and install the package such that it can be removed again later. An alternative to compiling from source is to use a precompiled binary package. In either case, any prerequisites/dependencies will be installed automatically by the package system, without need for manual intervention.
pkgsrc supports not only the hardware platforms that run NetBSD, but also — with the help of an autoconf-based bootstrap system — several other Unix-like operating systems, such as Linux, other BSD variants like FreeBSD, Solaris, Darwin/Mac OS X, IRIX, Interix and others. pkgsrc has also been adopted as the official package system for DragonFly BSD.
Symmetric multiprocessing
NetBSD has had support for SMP since the NetBSD 2.0 release in 2004, which was initially implemented using the giant lock approach. During the development cycle of the NetBSD 5 release, major work was done to improve SMP support; most of the kernel subsystems were modified to be MP safe and use the fine-grained locking approach. New synchronization primitives were implemented and scheduler activations was replaced with a 1:1 threading model in February 2007. A scalable M2 thread scheduler was implemented, though the old 4.4BSD scheduler still remains the default but was modified to scale with SMP. Threaded software interrupts were implemented to improve synchronization. The virtual memory system, memory allocator and trap handling were made MP safe. The file system framework, including the VFS and major file systems were modified to be MP safe. Since April, 2008 the only subsystems running with a giant lock are the network protocols and most device drivers.
Security
NetBSD provides various features in the security area. The Kernel Authorization framework (or Kauth) is a subsystem managing all authorization requests inside the kernel, and used as system-wide security policy. It allows external modules to plug-in the authorization process. NetBSD also incorporates exploit mitigation features, ASLR, MPROTECT and Segvguard from PaX project, and GCC Stack Smashing Protection (SSP, or also known as ProPolice, enabled by default since NetBSD 6.0) compiler extensions. Verified Executables (or Veriexec) is an in-kernel file integrity subsystem in NetBSD. It allows the user to set digital fingerprints (hashes) of files, and take a number of different actions if files do not match their fingerprints. For example, one can allow Perl to run only scripts that match their fingerprints. The cryptographic device driver (CGD) allows using disks or partitions (including CDs and DVDs) for encrypted storage.
Virtualization
The Xen virtual-machine monitor is supported in NetBSD since the 3.0 release. To use Xen, the system requires a special pre-kernel boot environment that loads a specialized Xen kernel as the "host OS" (known as Dom0). Any number of "guest OS" (known as DomU) virtualized computers, with or without (using "hypervisor" options) specific Xen/DomU support, can be run in parallel with the appropriate hardware resources.
With NetBSD 5, which greatly improves disk I/O and network I/O performance over NetBSD 4, some guest Operating Systems running under Xen are known to operate faster than when installed natively on the same hardware without NetBSD and Xen behind the scenes. The need for a boot manager, such as GRUB, was also eliminated with NetBSD 5's new built-in Xen-compatible configurable boot manager.
User-space virtualization such as VirtualBox and QEMU are also supported on NetBSD.
Storage
NetBSD includes many enterprise features like iSCSI, a journaling filesystem, logical volume management and the ZFS filesystem.
The WAPBL journalling filesystem, an extension of the BSD FFS filesystem, was contributed by Wasabi Systems in 2008.
The NetBSD Logical Volume Manager is based on a BSD reimplementation of a device-mapper driver and a port of the Linux Logical Volume Manager tools. It was mostly written during the Google Summer of Code 2008.
The ZFS filesystem developed by Sun Microsystems was imported in to the NetBSD base system in 2009. Currently, the NetBSD ZFS port is based on ZFS version 13.
Compatibility with other operating systems
At the source code level, NetBSD is very nearly entirely compliant with POSIX.1 (IEEE 1003.1-1990) standard and mostly compliant with POSIX.2 (IEEE 1003.2-1992).
NetBSD also provides system call-level binary compatibility on the appropriate processor architectures with several UNIX-derived and UNIX-like operating systems, including Linux, other BSD variants like FreeBSD, Apple's Darwin, Solaris and SunOS 4. This allows NetBSD users to run many applications that are only distributed in binary form for other operating systems, usually with no significant loss of performance.
A variety of "foreign" disk filesystem formats are also supported in NetBSD, including FAT, NTFS, Linux ext2fs, Mac OS X UFS, RISC OS FileCore/ADFS, AmigaOS Fast File System, IRIX EFS and many more through FUSE.
Licensing

All of the NetBSD kernel and most of the core userland source code is released under the terms of the BSD License (two, three, and four-clause variants). This essentially allows everyone to use, modify, redistribute or sell it as they wish, as long as they do not remove the copyright notice and license text (the four-clause variants also include terms relating to publicity material). Thus, the development of products based on NetBSD is possible without having to make modifications to the source code public. In contrast, the GPL stipulates that changes to source code of a product must be released to the product recipient when products derived from those changes are released.
On June 20, 2008, the NetBSD Foundation announced a transition to the two clause BSD license, citing concerns with UCB support of clause 3 and industry applicability of clause 4.
NetBSD also includes the GNU development tools and other packages, which are covered by the GPL and other open source licenses. As is the case for the other BSD projects, NetBSD separates those in its base source tree, in order to make removal of code under more restrictive licenses easier. There is no distinction made for ports.
Releases

The following table lists major NetBSD releases and their notable features in reverse chronological order. Minor and patch releases are not included.
Colour Meaning
Green Release still supported
Red Release no longer supported
Major releases Release date Notable features and changes
5.0 April 29, 2009 Rewritten threading subsystem based on a 1:1 model and rewritten scheduler implementation. Support for kernel preemption, POSIX real-time scheduling extensions, processor-sets, and dynamic CPU sets for thread affinity. Added jemalloc memory allocator. A metadata journaling for FFS, known as WAPBL (Write Ahead Physical Block Logging). Rewritten kernel modules framework, which will replace old LKMs.
4.0 December 19, 2007 Added support for slab allocator, iSCSI target, CARP, tmpfs, Xen 3, the Kernel Authorization framework, Veriexec and other security extensions, and a Bluetooth protocol suite.
3.0 December 23, 2005 Support for Xen 2.0 was added. Support for filesystems > 2 terabytes added. Pluggable Authentication Modules added. OpenBSD Packet Filter was integrated as an alternative to IPFilter. UFS directory hash support.
2.0 December 9, 2004 Addition of native POSIX threads and SMP support on i386 and other platforms. AMD64 architecture added. Support for UFS2 and SMBFS, addition of kqueue.
1.6 September 14, 2002 Unified Buffer Cache (UBC) was introduced, which unifies the filesystem and virtual memory caches of file data. Zero-copy support for TCP and UDP transmit path. Ten new platforms supported. New implementation of cross-building (build.sh) infrastructure. Added support for multibyte LC_CTYPE locales.
1.5 December 6, 2000 IPv6 and IPsec were added to the network stack. OpenSSL and OpenSSH imported. New implementation of rc.d system start-up mechanism. Start of migration to ELF-format binaries. A ktruss utility for kernel tracing was added. Six new platforms supported, including SPARC64. Added FFS soft updates and support for NTFS.
1.4 May 12, 1999 UVM, a rewritten virtual memory subsystem, was introduced. Added RAIDframe, a software RAID implementation, and imported IPFilter. Completion of the integration of all remaining 4.4BSD Lite-2 kernel improvements. Ports to Power Macintosh and NeXTcube/station systems added. Added full USB support.
1.3 March 9, 1998 XFree86 source tree was made a supported part of the distribution. Support for ISA Plug and Play, PCMCIA, ATAPI and APM added. ext2fs and FAT32 filesystems added. The pkgsrc packages collection system was introduced.
1.2 October 4, 1996 Support for NFSv3, SCSI scanner and medium changer devices added. NTP phase-locked loop added in kernel. Ports for ARM and Sharp X68k systems added.
1.1 November 26, 1995 Ports for DEC Alpha, Atari TT/Falcon030 and MVME68k systems added. Binary emulation facility added. Generic audio subsystem introduced.
1.0 October 26, 1994 The first multi-platform release, supporting the PC, HP 9000 Series 300, Amiga, 68k Macintosh, Sun-4c series and the PC532. Also in this release, the legally encumbered Net/2-derived source code was replaced with equivalent code from 4.4BSD-lite, in accordance with the USL v BSDi lawsuit settlement. Addition of shared libraries and Kerberos 5.
0.9 August 20, 1993 Contained many enhancements and bug fixes. This was still a PC-platform-only release, although by this time work was underway to add support for other architectures. Support for loadable kernel modules (LKM).
0.8 April 20, 1993 The first official release, derived from 386BSD 0.1 plus the version 0.2.2 unofficial patchkit, with several programs from the Net/2 release missing from 386BSD re-integrated, and various other improvements.
Logo

The NetBSD "flag" logo, designed by Grant Bissett, was introduced in 2004 and is an abstraction of their older logo, designed by Shawn Mueller in 1994. This was based on the famous World War II photograph Raising the Flag on Iwo Jima, which some perceived as culturally sensitive and inappropriate for an international project.
The NetBSD Foundation

The NetBSD Foundation is the legal entity that owns the intellectual property and trademarks associated with NetBSD, and on January 22, 2004, became a 501(c)3 tax-exempt non-profit organization. The members of the foundation are developers who have CVS commit access. The NetBSD Foundation has a Board of Directors, elected by the voting of members for two years.
Examples of use

NetBSD was used in NASA's SAMS-II Project of measuring the microgravity environment on the International Space Station, and for investigations of TCP for use in satellite networks.
NetBSD's clean design, high performance, scalability, and support for many architectures has led to its use in embedded devices and servers, especially in networking applications.
A commercial real-time operating system, QNX, uses a network stack which is based on NetBSD code , and provides various drivers ported from NetBSD.
Force10 Networks uses NetBSD as the underlying operating system that powers FTOS (the Force10 Operating System), which is used in high scalability switch/routers. Force10 also made a donation to the NetBSD Foundation in 2007 to help further research and the open development community.
Wasabi Systems provides a commercial Wasabi Certified BSD product based on NetBSD with proprietary enterprise features and extensions, which are focused on embedded, server and storage applications.
NetBSD was used in NASA's SAMS-II Project of measuring the microgravity environment on the International Space Station, and for investigations of TCP for use in satellite networks.
In 2004, SUNET used NetBSD to set the Internet2 Land Speed Record. NetBSD was chosen "due to the scalability of the TCP code".
NetBSD is also used in Apple's Airport Extreme and Time Capsule products, instead of their own Mac OS X (which uses FreeBSD's userland) platform.
The operating system of the T-Mobile Sidekick LX 2009 smartphone is based on NetBSD.
Hosting

Hosting for the project is provided primarily by the Internet Systems Consortium Inc, the Luleå University of Technology, Columbia University, and Western Washington University. Mirrors for the project are spread around the world and provided by volunteers and supporters of the project.

(From http://en.wikipedia.org/wiki/Netbsd on 05/21/2010)

OpenSolaris

OpenSolaris is an open source operating system based on Sun Microsystems' Solaris. It is also the name of the project initiated by Sun to build a developer and user community around it.
OpenSolaris is derived from the Unix System V Release 4 codebase, with significant modifications made by Sun since it bought the rights to that code in 1994. It is the only open source System V derivative available. Open sourced components are snapshots of the latest Solaris release under development. Sun has announced that future versions of its commercial Solaris operating system will be based on technology from the OpenSolaris project.

History

OpenSolaris is based on Solaris, which was originally released by Sun in 1991. Solaris is a version of SVR4 (System V Release 4) UNIX, co-developed by Sun and AT&T. It was licensed by Sun from Novell to replace SunOS.
Planning for OpenSolaris started in early 2004. A pilot program was formed in September 2004 with 18 non-Sun community members and ran for 9 months growing to 145 external participants.
The first part of the Solaris codebase to be open sourced was the Solaris Dynamic Tracing facility (commonly known as DTrace), a tracing tool for administrators and developers that aids in tuning a system for optimum performance and utilisation. DTrace was released on January 25, 2005. At that time, Sun also launched the opensolaris.org web site, and announced that the OpenSolaris code base would be released under the CDDL (Common Development and Distribution License). The bulk of the Solaris system code was released on June 14, 2005. There remains some system code that is not open sourced, and is available only as pre-compiled binary files.
A Community Advisory Board was announced on April 4, 2005: two were elected by the pilot community, two were employees appointed by Sun, and one was appointed from the broader free software community by Sun. The members were Roy Fielding, Al Hopper, Rich Teer, Casper Dik, and Simon Phipps. On February 10, 2006 Sun reestablished this body as the independent OpenSolaris Governing Board. The task of creating a governance document or "constitution" for this organization was given to the OGB and three invited members: Stephen Hahn and Keith Wesolowski (developers in Sun's Solaris organization) and Ben Rockwood (a prominent OpenSolaris community member).
On March 19, 2007, Sun announced that it had hired Ian Murdock, founder of Debian, to head "Project Indiana", an effort to produce a complete OpenSolaris distribution, with GNOME and userland tools from GNU, plus a network-based package management system.] Several independent distributions are also available.
On December 1, 2008, OpenSolaris 2008.11 was released, in versions that could be booted as a Live CD or installed directly. It uses the GNOME desktop environment as the primary user interface. The release includes a GUI for ZFS' snapshotting capabilities, that provides functionality similar to Mac OS X's Time Machine.
In December of 2008 Sun Microsystems and Toshiba America Information Systems announced plans to distribute Toshiba laptops pre-installed with OpenSolaris.

License

Main article: Common Development and Distribution License
Sun has released most of the Solaris source code under the Common Development and Distribution License (CDDL), which is based on the Mozilla Public License (MPL) version 1.1. The CDDL was approved as an open source license by the Open Source Initiative (OSI) in January 2005. Files licensed under the CDDL can be combined with files licensed under other licenses, whether open source or proprietary.
During Sun's announcement of Java's release under the GNU General Public License (GPL), Jonathan Schwartz and Rich Green both hinted at the possibility of releasing Solaris under the GPL, with Green saying he was "certainly not" averse to relicensing under the GPL. When Schwartz pressed him (jokingly), Green said Sun would "take a very close look at it." In January of 2007, eWeek reported that anonymous sources at Sun had told them OpenSolaris would be dual-licensed under CDDL and GPLv3.[12] Green responded in his blog the next day that the article was incorrect, saying that although Sun is giving "very serious consideration" to such a dual-licensing arrangement, it would be subject to agreement by the rest of the OpenSolaris community.

(Copied from http://en.wikipedia.org/wiki/OpenSolaris on December 31, 2008)

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