You need install Mono on Linux. If your .NET app using .NET 2.0, you can run you app on Linux. I'm using Ubuntu 11.04 and run KeePass 2.15, a .NET open source. Just exit to terminal and type "mono KeePass.exe" Using MonoDevelop, you can develop a C# application on Ubuntu. Also, you can run ASP.Net and C# on Ubuntu too.
