At OSCON 2010 this week Puppet Labs (formerly Reductive Labs) just received $5M in Series B funding from Kleiner Perkins Caufield & Byers, following $2M of Series A funding they received just last year from True Ventures.

If these guys sound familiar, you will remember the interview with Luke Kanies on FLOSS 93 with Leo Laporte and Randal Schwartz. As is typical of the show, they got a broad spectrum from uber-technical to the non-technical.

Puppet Details
The technology platform for Puppet is based on Ruby and therefore runs anywhere that Ruby runs. It's a distributed architecture based on a combination of XML-RPC and RESTful services. It's divided into core components and optional modules. It was inspired by frustrations with Cfengine v2 (see below).

The current stable version is 0.25.5, the cutting edge is 2.6.0rc4 and the legacy version is 0.24.9. You can find more information and downloads here.

They have an active community and are on Twitter.
What does it do?
On the micro level, tools of this type are designed to automate the configuration of servers. Not so much a single server, but a group of server. Looking down the stack you'll see them slightly above single server configuration components such as "webmin" and "openpanel". Looking up the stack you'll see software for managing clouds such as cloudmin.

On the macro level they allow you to control entire fleets of servers and manage a complete data center. From bootstrapping the OS all the way up to individual service configurations. This is for multiple platforms (UNIX at this point, but they are promising Windows soon).

Why it's so successful?
This project is so successful because the founder made one of his primary goals be that it's financially stable and profitable from the beginning. If you listen to the FLOSS podcast, you will see just how organized and driven Luke is. I am sure he has made a number of sacrifices throughout the history of this project and I really salute him for his dedication and I am inspired by his success.

Competitors
Cfengine:
Luke freely admits that he re-wrote the parser for Cfengine 2.x at one point when he was trying to decide if he should fork that or start out on his own. Covered on FLOSS 106.
Virtualmin:
Based on webmin (using it as an agent/component of the sytem). Covered on FLOSS 110.
OPSCODE:Chef:
They focus on a system that is aimed at making your infrastructure configurable as if it was code (pulled from their website) and has an Apache License and a strong community.
LCFG:
A system for managing large numbers of essentially heterogeneous UNIX systems.