I'm not sure why something with heavy requirements needs to be on the web. Just make it a stand-alone application if it has such dependencies. Everyone seems to be in round two of being crazy for the web.

I'd actually like to see the results, but I'm not going to install Silverlight either.

EDIT: Here's my litmus test. If it doesn't work on multiple (different) browsers on different OSes without installing additional support plugins or programs, it shouldn't be a "web app."