This year we picked five startups commercializing open source projects to which they contribute that are especially strong going into 2012. The list is in no particular order.

Puppet Labs is a startup founded by Luke Kanies, the creator of Puppet, an open source configuration automation tool.

Puppet has become virtually synonymous with DevOps in the same way that Amazon Web Services has become synonymous with cloud. I expect this to change as DevOps becomes more mainstream and more vendors enter the market, but for now it seems that you can hardly discuss the idea of DevOps without talking about Puppet.

Meanwhile, the company has managed to quickly own its technology space. Its main competitor, Chef, has seen slower adoption. This isn’t a slight towards Chef, or to Opscode, the company that commercializes it. But it is a big validation for Puppet and its ease of use.

Puppet Labs was founded as “Reductive Labs” to provide Puppet support and consulting. It changed its name to Puppet Labs last year and launched its first product, Puppet Enterprise. The company raised $2 million series A in 2009, a $5 million round series B in 2010 and a $8.5 series C this year for a total of $15.5 million. Many are already asking whether Puppet Labs will file for an IPO in 2012.

As more companies invest in Hadoop clusters and cloud deployments you can be sure that Puppet and Puppet Enterprise will be top list. You can find out more about the company and see watch our interview with Kanies here.

More Open Source Startups to Watch

Puppet Labs

Revolution Analytics

Joyent

Opscode