The blogger David Span have installed Fireworks on his Ubuntu box in order to use it instead of Gimp
See here how he did it – http://davidspan.com/2006/10/30/install-fireworks-on-ubuntu/
When I installed Ubuntu on my laptop I decided to learn Gimp. Well that didnt go very well, so I tried a few others. But after a week I must say they just dont toe the line, at least not for me.
Dont get me wrong; they all have their benefits. However I have been using fireworks for a very long time. I know it to well and realy lack the time to learn gimp.