C# FAQ: Does .NET run only on Windows

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Does .NET run only on Windows?

Even if you do not operate a machine running the Windows operating system, it may still be possible to run .NET. There are several open source projects to create Common Language Runtime (CLR) systems which function on other operating systems, e.g., BSD, Linux.

Two prominent open source projects are:

• Mono - open source multi-platform system
• ROTOR - Microsoft Shared Source implementation for FreeBSD, Mac OS X 10.2, and Windows XP.

Since .NET is the Microsoft trademark for it's Windows implementation of the CLR and related technologies, the preceding projects are not—strictly speraking—.NET implementations. And, these open source implementations may not cover all the framework and related libraries available in .NET. On the other hand, they may contain libraries which are not found in .NET. However, these implementations allow the compiling and running of C# programs on non-Windows platforms.