AVR-LibC

AVR-LibC is a Free Software project whose goal is to provide a high quality C library for use with GCC on Microchip (formerly Atmel) AVR microcontrollers.

Together, AVR-binutils, AVR-GCC, and AVR-LibC form the heart of the Free Opensource Software toolchain for the Microchip AVR microcontrollers.

AVR-LibC is licensed under a single unified license. This so-called modified Berkeley license is intented to be compatible with most Free Software licenses like the GPL, yet impose as little restrictions for the use of the library in closed-source commercial applications as possible.