Digital BW, The Print

As was said before, it costs nothing to try it. Should be no harm 
looking at the software and trying to understand how to use it. There 
is no official licensing or nags, so  there is no limit to the number 
of days in the trial. If you like, contribute to the designer, if not 
simple uninstall it and try something else.

You may also want to try the Bowhaus RIP, which sells for $250, but 
may have an interface that you like better (then again it may not).