We're currently running a Windows/IIS/MSSQL/ASP.Net3.5 stack for internal development and it's great, mostly for the developers who are enjoying the tight integration with Visual Studio etc.
Problem is, we want to scale and don't want to be tied to a Microsoft OS. These days Linux+Mono is looking very interesting, but I don't know of many businesses who have done the WISA to open source port, particularly for a .Net3.5 codebase.
I'd like to if anyone else has done this, for a production environment, and if the result were good, bad or ugly.