Is “Xprint” “mozilla”-only (I saw that its hosted by mozdev.org) ?
No, Xprint is a general-purpose print API based on X11 used by many applications – mozdev.org is just one of the hosting places (others are http://xprint.freedesktop.org/ (bugzilla, CVS) and http://www.sourceforge.net/projects/xprint/ (download area)) hosting the development area, documentation and mailinglist. :).