In this page you can download the Arduino specific libraries and some other third party library that could be useful.
Specific Archiduino 32U4 libraries
Specific Archiduino 1284 libraries
Work in progress…
Third Party libraries
LiquidCrystal_I2C: we fixed a function in LiquidCrystal_I2C.cpp in order to allow it working with Arduino IDE 1.6.4, 1.6.5, 1.6.6, 1.6.7 and the latest 1.6.8 revision.