Arduino IDE 1.6.4 is now available for download.
Here is a brief list of important changes:
- Added support to the new Arduino Gemma
- Tools submenu shows selected subentry. Thanks Paul Stoffregen
- Added a command line interface to Boards and Libraries Managers: see –install-boards and –install-library actions in the documentation
- Restored line highlighting when the sketch contains an error. This was actually a regression, something that stopped working since 1.5.7
- Fixed an error that left the Tools > Port menu greyed out
More Info: Arduino Blog