Apache will support ASP if you buy Chilisoft's ChiliASP engine.
However, if you set up Apache on, for example port 8080 and have IIS running on port 80, then they will not conflict.
Saying that, however, I am running IIS, with PHP4 and mySQL. By doing that, I can make my pages in PHP, ASP and hook up to mySQL without a problem.
Hope that helps in some small way.
Cheers,
Neil