Photoshop for Linux

Picasa is a photo organizer, with a few photo adjustment tools.  However for real photo manipulation the program that defines the category is Photoshop.

To get Picasa working on Linux, Google use Wine - a layer that allows Windows applications to work on Linux.  Google have also extended their work (via hiring of CodeWeavers, Googlers working their normal jobs and in their 20% time, interns, and Summer Of Code students) so that Photoshop also works pretty well on Linux.

More details at the Google Open Source Blog and the Wine-Devel list.