It doesn't happen all the time, but it does happen occassionally where I want to run multiple instances of Macromedia Homesite. Usually, when you try to launch it more than once, it just throws focus to the existing instance. But, I just found a great fix for that.
On http://www.wilk4.com/asp4hs/tips.htm, they had a registry edit that would allow multiple instance of Homesite to open. It's awesome. Sometimes I am looking in so many places at once, this is the only way I could hope to keep it under control.
Using RegEdit on windows, I just found the key:
and added the following string-value pair (STRING value):
- allowMultipleInstances = -1