If you need a "standalone" CLR debugger (such as .NET 2 offered), SharpDevelop is a good alternative to VS (if you're into that kind of thing).
However, when trying to debug a running ASP.NET application, I did not see w3wp
listed in "Attach to Process". Why not?
In the spirit of "Q&A-style" sharing, I'm posting this item I've already figured out. I found that there were two somewhat non-obvious requirements.