2. Choose Mono, an open source framework based on C#, which is a project hosted by Novell Company (formerly Ximian). C# is a. NET language introduced by Microsoft, which can only run in. NET platform, such as Win9x, ME, NT, 2000, XP, WinCE and other operating systems. But MONO is to be transplanted. NET and its programming language are ported to non-Windows platforms. Now, C# is unique. NET language that has been ported to non-Windows platform.