"The folks at Projity sent me a note on Friday about reaching
the 200,000 download mark for their open source project management
software, OpenProj. OpenProj is released under the Common Public
Attribution License (CPAL). It runs on Linux, Windows, and Mac OS X
and it opens Microsoft Project and Primavera files.
"I used a previous version and thought it worked rather well
though I am not that well-versed in project management software. If
you are in need of project management software it's definitely
worth a look..."