I use 37Signals' Campfire at work. And I'm on Windows 7.
Flare didn't work for me. It just keeps throwing errors at me.
So is there a good application to use with Campfire?
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According to the 37 Signals site (http://campfirenow.com/extras), Flare is the only Campfire app for Windows.
The only other alternative is to run Campfire in an application specific browser such as Mozilla Prism