A public demo version of Tonescape is now available. I haven't had a chance to try it out yet, but it looks like it has a lot of useful features. You can download it for free at this link.
Please be advised that this software is new and still has some bugs. I also hear that the help pages aren't complete yet. Understandably, some people may want to try it out right away and others may choose to wait a while. I welcome any comments from those who have tried this software and I may discuss it further when I have had a chance to use it and understand it better. There's also a Yahoo group for discussing Tonescape.
This software is only one feature at the Tonalsoft website. Be sure to visit for a wealth of information on microtonal music.