Mono 2.0 released on 6 Oct 2006.
Mono allow you to run ASP.NET, C# applications on Linux.
Mono is a software platform designed to allow developers to easily create cross platform applications. It is an open source implementation of Microsoft’s .Net Framework based on the ECMA standards for C# and the Common Language Runtime. We feel that by embracing a successful, standardized software platform, we can lower the barriers to producing great applications for Linux.