Microsoft takes lid off .Net Common Language Runtime sauce

In keeping with its plan to release all of its .Net Core development platform as open-source software, Microsoft on Tuesday published the code to CoreCLR, the .Net Core code execution runtime.

"CoreCLR is the .Net execution engine in .Net Core, performing functions such as garbage collection and compilation to machine code," Redmond's .Net team said in a blog post on Tuesday.

The tool is an open-source version of the .Net Framework's Common Language Runtime, which in Microsoft's platform serves a role similar to the Java Virtual Machine.

The release comprises some 2.6 million lines of code written in a combination of C++ and C#, Microsoft said, including 320,000 lines for the just-in-time (JIT) compiler and 55,000 lines for the garbage collector.

This isn't the cross-platform .Net future that Microsoft has been hinting at, though. The current version of CoreCLR will only build and run on Windows, although Linux and OS X implementations are supposedly coming in the next few months.

The build process for the code is based on CMake, a cross-platform family of tools that's available for all three operating systems. Redmond said it chose CMake out of several available options "based on advice."

This is Redmond's second major release of .Net Core source code, following the release of the platform's core libraries as the CoreFX project in November.

The software giant has published both projects under the MIT License, a permissive open-source license that allows the code to be used in other software – even commercial, proprietary software – regardless of whether the developer makes source code available.

"We hope to see many community contributions to the codebase, too," Microsoft said. "We're in the process of bringing more of our validation infrastructure to the open source environment to make it easier to make contributions."

Microsoft says you can now expect new commits to show up in the CoreCLR code base daily, as has been the case with CoreFX.

If you'd like to play around with the code today, you can find it at the project's official repository on GitHub.

Microsoft has also scheduled a free "virtual conference" where all things about .Net will be discussed on March 18 and 19. You'll be able to view more than 16 hours of streaming content here. ®