Here are the release notes:

Terminal

  • Many layout glitches have been solved -particularily in emacs
  • Fixed a bug that was causing text to overwrite rather than insert
  • Dark grey text is now visible

Rendering

  • Choose between Minimal, Low, Medium, and High rendering modes
  • Moving effect sliders down to 0 improves performance
  • Selection is visible for black text on a white background

Other

  • Supports Mac OS X 10.8 Mountain Lion
  • ARC and modern Objective-C used under the hood
  • No more crashes when deleting shortcuts