When the .NET Foundation was announced at Microsoft’s Build Conference in San Francisco on April 3, it was not the first time the giant software company had created a non-profit spinoff to expand its open-source offerings. In fact, the idea began as early as 2006 with the foundation of Codeplex. The new idea here, instead, is the actual Roslyn project itself.

The roots of open-source engagement at Microsoft go back even further than 2006, but the thought of opening the C# runtime was not a realistic part of the equation, said Sam Ramji, Microsoft’s former leader of worldwide open-source and Linux strategy, and current Outercurve Foundation board secretary. He also launched Codeplex, a Microsoft-backed repository of open-source .NET and Windows projects.

Ramji said that Microsoft had been kicking around the name “The .NET Foundation” as early as 2005. “In 2009, we decided to hone it around the forge as Codeplex, but that concept has been brewing inside the company for at least eight years,” he said.

(Related: Microsoft starts up the .NET Foundation)

Ramji said that this new foundation, however, shows a decision within Microsoft to do things that he and his team had only theorized about when he worked there.

“The open-sourcing of the CLI and CLR is very new, and pretty important technically,” said Ramji. “When you think about Java, it’s not just about Java anymore. It’s about the JVM. We have Scala, a JVM language, Grails, another JVM language. At Apigee [Ramji’s current employer], we use Riemann for cloud-scale event processing. That’s built on top of Clojure, which is Lisp on the JVM.”

As for whether or not Microsoft is responding to the growth in JVM-based languages by open-sourcing the Roslyn runtime, Gianugo Rabellino, senior director of open-source communities at Microsoft Open Technologies, said that the project will foster new opportunities for Microsoft’s partners.

“We have found that community engagement through open-source foundations has been proven to nurture and advance core technologies that the IT industry relies upon,” he said. “Developers everywhere are innovating rapidly with the power and flexibility of .NET, and the growing community is in need of a developer forum, a test bed, practices and processes that will strengthen the future of the .NET ecosystem.

“Having the newly open-sourced .NET Compiler Platform [Roslyn] in the .NET Foundation enables exciting new scenarios for the .NET and Visual Studio partner ecosystem, who can deeply understand the compiler platform and participate in its evolution.”

Another possible reason for Microsoft’s interest in building out the open-source community around its .NET Compiler Platform is that the modern computing landscape requires the support of many different platforms, from mobile devices to Web-based systems and desktops. As a result, Xamarin has seen great success with its cross-platform development solutions for .NET.

“I think Microsoft is much more interested now, especially with the new CEO,” said Paul Betts, an advisor to the .NET Foundation and a developer at GitHub. “They’re willing to branch out and sell any kind of software to people, which is very cool.

“In my opinion, Xamarin is super exciting. If you build your applications right, you can have native applications take advantage of everything the platform does, but be able to reuse a lot of the code you’ve written.”

Xamarin has contributed six projects to the .NET Foundation, and its CEO and founder, Miguel de Icaza, is on the board of directors.

Microsoft remains engaged with the Outercurve Foundation, a non-profit created by the company in 2009 as the Codeplex Foundation—a separate entity from the actual Codeplex site. Erynn Petersen, executive director of the Outercurve Foundation, said that the establishment of the .NET Foundation makes the mission of Outercurve even clearer.

“We’ve gone back and forth [with the .NET Foundation], and we’re very supportive of them getting off the ground,” she said. “We found, over the last quarter particularly, working with all of the open-source foundations has been beneficial to us. I’m looking at the .NET Foundation as another foundation in the open-source ecosystem. For Outercurve, I think a lot of people were looking at us for a while, and [wondering] how Outercurve is contributing to the open-source community. The establishment of the .NET Foundation clearly answers that. This allows us to have a lot of clarity.”

That’s because the .NET Foundation can focus on the code developers need to do their jobs, while Outercurve can focus on providing the communication between developers, vendors and projects that enable collaboration, said Petersen.