.NET is open-source

Open-source on GitHub

.NET Core is an open-source and cross-platform version of .NET that is maintained by Microsoft and the .NET community on GitHub.

All aspects of .NET Core are open-source including class libraries, runtime, compilers, languages, ASP.NET Core web framework, Windows desktop frameworks, and Entity Framework Core data access library.

Visit .NET on GitHub

MIT and Apache 2 licenses

The various parts of .NET Core are maintained in different GitHub repositories. These repositories typically use the MIT or Apache 2 licenses. Some repositories license documentation and other forms of content under Creative Commons Attribution 4.0.

See specific repositories to understand the license used.

More than just code

In addition to the code we aim to make every aspect of .NET as open as possible. The documentation is open-source. On the .NET team at Microsoft we open up our day to day work with initiatives like our open API review process and the community standups.

The Open-source library guidance provides recommendations for .NET developers to create high-quality .NET libraries. Of course, the guidance itself is open-source on GitHub and developed in partnership with popular library authors.