Mono

Mono, the open source development platform based on the .NET framework, allows developers to build Linux and cross-platform applications with improved developer productivity. Mono's .NET implementation is based on the ECMA standards for C#  and the Common Language Infrastructure.

Mono includes both developer tools and the infrastructure needed to run .NET client and server applications. It is positioned to become the leading choice for development of Linux applications.

Mono includes compilers, an ECMA-compatible runtime engine (the Common Language Runtime, or CLR), and many libraries. The libraries include Microsoft .NET compatibility libraries (including ADO.NET, System.Windows.Forms and ASP.NET), Mono's own and third party class libraries.Gtk#, a set of .NET bindings for the gtk toolkit and assorted GNOME libraries can be found in the latter.

This library allows you to build fully native Gnome application using Mono and includes support for user interfaces built with the Glade interface builder.

Furthermore, Mono's runtime can be embedded into applications for simplified packaging and shipping. In addition, the Mono project offers an IDE, Debugging, and a documentation browser.

Main Features:
- Multi-platform.
- Based on the ECMA/ISO standards.
- Runs ASP.NET and Winforms applications.
- Can run .NET, Java, Python and more.
- Open Source, Free Software.
- Commercially supported.
- Comprehensive technology coverage.