avr-libc C library for use with GCC on Atmel AVR microcontrollers
AVR Libc is a Free Software project whose goal is to provide a high quality C library for use with GCC on Atmel 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.