Hello, As many have already noticed, the current release version of ChucK does not run in real-time audio mode on Mac OS X Lion. Until now! In advance of a formal release, we are providing builds of the current SVN source for anyone who is having trouble getting ChucK to run on Lion. ChucK (Mac OS X Universal command line executable): https://ccrma.stanford.edu/~spencer/chuck/chuck-1.2.1.4-beta-1.tgz miniAudicle (Mac OS X Universal binary): https://ccrma.stanford.edu/~spencer/chuck/miniAudicle-0.2.1-beta-1.tgz Lion users, please let us know if you continue to have difficulties with real-time audio with these builds. Updating ChucK to use the latest version of RtAudio fixed a host of Lion issues; a minor bugfix in RtAudio resolved the remaining issue. There are a lot of other cool things coming too when the new version of ChucK is released. Special thanks to Gary Scavone for making peace between Mac OS X Lion and RtAudio. Peace! spencer + chuck team