[saltcured]

After seeing this whole thread a day late, I have to wonder: is the unspoken difference what "cross-platform" and "always" mean to different posters? To someone with my historical perspective, it grates a bit to see X Windows conflated with Linux as a platform.

My memory of the early days is consistent with what the wikipedia page says about GIMP. It was cross-platform on the typical Unix workstations that were around the UC Berkeley campus labs and XCF. This was things like Solaris, SunOS, HP-UX, Ultrix, and Irix.

Students in this milieu were just as likely to have some BSD variant on their home PC as Linux. I think it was later during and after the "Beowulf" scientific computing period when Linux started to dominate as the Unix-like platform for open source development.