asp.net is supported.
You may need to add 'DirectoryIndex default.aspx' to your .htaccess to get it to work
ASP.NET is supported via Mono, running on linux, so you need to take this into consideration. Example: with Linux, files are case sensitive, so under windows, default.aspx and Default.aspx are the same file, while under Linux they would be 2 separate files.
Currently .NET 2.0 is whats supported(3.5 and 4 MAY work because the mono version is 2.6, but no guarantees)