As GigaOm notes, San Francisco-based startup Engine Yard has raised $19 million in a third round of venture capital funding from DAG Ventures, Bay Partners, and Presidio Ventures (a Sumitomo Corporation company). The investment follows a total investment of $18.5 million in the company in 2008 from Benchmark Capital and other investors, one of which was Amazon.

Engine Yard offers a cloud-based hosting environment for Ruby on Rails applications.  Ruby on Rails is an open source software framework that underlies Twitter and many other well-known applications. You can find many notable applications based on it at Open Source Rails. With substantial funding under its belt, Engine Yard's next move may be to expand its support and services business, a la Red Hat.

Let's face it, open source software companies and projects have a wide variety of innovative platforms and methods to drum up awareness, business, and interest in development for the projects they create and support. The problem is, it's not always easy to quantify how much interest and awareness (or ultimately, new contributors, users, or customers) result from any specific method.

Social networks are a great way to reach out to people with specific interests and start the chain of "word of mouth" recommendation. But they just aren't the traditional sort of public relations drives or advertising many organizations are used to. If an organization understands this, there's a lot to gain from social network outreach -- and open source software, a model that works based on input from the wider community, is in a position to benefit even more.

There's just that matter of metrics -- will the push yield good results? Engine Yard, a Ruby on Rails hosting and services provider, found it's well worth the effort.

Engine Yard, which specializes in cloud computing and open source tools for Ruby and Rails applications, has announced a new open source framework called Merb. "Ruby continues to be one of the fastest growing programming languages in terms of adoption," said Ezra Zygmuntowicz, founder of the Merb project and co-founder of Engine Yard. "Merb offers Ruby programmers another choice for building Ruby applications." What's unique about it?