OpenOffice.org
Apparently today was Document Freedom Day. Next year we shall have to actually celebrate it. At work, one of the company's key objectives is to promote open standards like ODF. We are lucky to have an OpenOffice.org developer in-house (a rare commodity, especially outside of Sun or Novell), and I've had the opportunity to work on supporting openoffice.org from time to time. The biggest difficulty is the sheer size - the built source tree needs 15GB, so it's pretty difficult to search through, for instance....