Suite of executable software development tools for Atmel AVR RISC processors, hosted on the Windows platform, has GNU GCC compiler for C/C++. Open source.
Official product information from Atmel Corp. Include overview, technical specifications, details of application support, and information about various associated tools and software.
Goal: high quality C library to use with GCC on Atmel AVR microcontrollers. Together, avr-binutils, avr-gcc, and avr-libc are the core of the open source toolchain for AVR.