Mono
Mono is a portable and open source implementation of the .NET framework. It has support for both 32 and 64 bit systems on a number of architectures as well as a number of operating systems:
  • Linux
  • Mac OS X, iPhone OS
  • Sun Solaris
  • BSD - OpenBSD, FreeBSD, NetBSD
  • Microsoft Windows
  • Nintendo Wii
Mono-compatible compilers:
C#, Java, Boo, Nemerle, Visual Basic.NET, IronPython, JavaScript, Oberon, PHP, Object Pascal, LUA, Cobra and others.

Built on an implementation of the ECMA Common Language Infrastructure and C#.

Mono's runtime, compilers, and libraries are distributed under OSI approved licenses and are available for dual-licensing.


MonoDevelop
MonoDevelop is an IDE primarily designed for C# and other .NET languages. MonoDevelop enables developers to quickly write desktop and ASP.NET Web applications on Linux, Windows and Mac OSX. MonoDevelop makes it easy for developers to port .NET applications created with Visual Studio to Linux and Mac OSX and to maintain a single code base for all platforms.


Articles

Validation of SVG Tiny.
Validation of SVG Tiny with a RELAX NG schema in C#.

XML validation with RELAX NG
A RELAX NG validator for .NET using Commons.Xml.Relaxng from Mono.


Links

Mono Home
Mono is a cross platform, open source .NET development framework.
http://mono-project.com/Main_Page

MonoDevelop
MonoDevelop is a free GNOME IDE primarily designed for C# and other .NET languages.
http://monodevelop.com/

Licencing
GPL, LGPL 2.0, MIT X11.
http://www.mono-project.com/License

Xamarin Home
Xamarin is the new home of the engineers that created Mono, MonoTouch and Mono for Android.
http://xamarin.com/