I know it's a late answer but this caught my eye. Last year I moved a very complex aplication from ASP.NET to run on unix using the Mono framework.
I found Mono and the MonoDevelop editor to be solid tools, and had no problems running my code natively on linux and osx.
Now you're talking about classic ASP. Mono does have the opensource "xsp" and "xsp2" web servers built in... I believe xsp can handle classic ASP.
Using Mono bought us the 12 weeks I needed to go heads down and convert the entire application to Python using web.py. I agree it's a great framework, especially if you want a lot of control and not be bound by a templating based system like Django.
Regarding Stare's comment... if you do virtualization I'd strongly recommend VirtualBox. Parallels has burned all their bridges with me.