Audacity 4.0 released

Version4.0 of the Audacity audio editor has been released. Notable changes in thisrelease include a rewritten interface using Qt, ability to save user-interfacelayouts as "Workspaces", improvements in working with audio clips, and a new.aup4 project format.

The release is not fully feature-compatible with the Audacity3.xseries; see the compatibilitynotes for a list of missing features.