Mono is a complete development platform based on Microsoft's .NET Framework, allowing IT professionals and ISVs to build Linux and cross-platform programs with great productivity.
The environment supports .NET client and server add-ons, with support across multiple platforms.
Once you download the program from its official website, you'll see that you can launch the platform from the system's start menu. This shortcut opens a shell (Mono Command) from which you can start working.
But one of the most important points is the community of programmers who collaborate on community projects so that they get finished. (Usually the community gets involved in projects with great potential.)
The platform is based on ECMA/ISO standards, and from its environment you can run ASP.NET, Winforms, .NET, Java, Python, etc.
Mono is really a very good GNU alternative for creating developments in a simpler way, with the support of a community willing to collaborate on good programming ventures.
Mono is a free program available for Windows, Mac OS X, and Linux.
