Rosegarden, the flagship digital audio workstation for Linux (see an interview with the developers),
has hit 1.0 PR1, making this the first release on the road to the final
1.0 release. This version is mostly bugfixes, but there's a significant
addition: latency compensation for plugins, a feature Apple's Logic
still lacks. Rosegarden is the most full-featured audio program for
Linux currently, and it's free to boot. (Things may really get
interesting if this hits OS X. Stay tuned.)