I've never heard of the Mono Project before, but it looks very interesting. Here's a link if anyone wants to check it out:
www.mono-project.com
I wonder how well optimized the .net applications will be when running on linux with Mono... They will probably run better in the native Windows environment, just my guess, though.
This Mono Project will probably help .Net be a bit more competitive with Java in regards to cross-platform compatibility.
In regards to Tomcat, I don't know if Mono will interfere. If you have a spare system, maybe just try it out. Or, if you don't have a spare system, you could probably test it using Microsoft Virtual PC to run a linux virtual server on your Windows workstation and test it from there. I used Microsoft Virtual PC with testing various CentOS configs and it worked fine.
