photoshop-like
GIMP is the favorite graphics editing program of many designers and graphic artists. It is free and compatible with Windows, Mac and Linux (the two big reasons for its popularity).
Handy Tweaks To Make GIMP Replace Photoshop - Smashing Magazine
PSPI is a GIMP plug-in that runs 3rd-party Photoshop plug-in filters. I wrote it in 2001, and it initially worked on Windows only. Then nothing much happened until March 2006 when it became available also on Linux. All that was needed, basically, was for somebody to try building it using winegcc. Possibly building and running it on Linux might have worked already years ago, but nobody tried... Thanks to Mukund for trying it on Linux and reporting the success!
Tor Lillqvist--PSPI: Running Photoshop plug-ins in GIMP
