For groupware related software, kolab, hula, opengroupware etc might be useful.
>Of course, photo journalists could use Gimp, and cartoonists may be able >to use ktoon or inkscape.
Gimp (upto version 2.2.8) does not support CMYK colorspaces, which appears to be important for publishing tasks. There is a plugin which provides partial functionality. Krita supports CMYK, openEXR, 32bit colors, etc. It also supports watercolor simulation.
Regards,
Balachandran.