Benjamin LeClerc, the author of Task Unifier, has announced that development of the software has ceased as of January 31, 2015 and the Pro version is now free for all users. He has said that he expects to fix any major bugs that might be found, but there will be no future modifications to the program.

http://sourceforge.net/p/taskunifier/discussion/general/thread/aa66c6c7/

Thanks for this info; Task Unifier was a good cross-platform task management software, and my task tool of choice for some time. The only reason I abandoned it was that my tasks have become much more collaboration-oriented, so I need a team solution rather than a personal one.