AVR Studio is a professional Integrated Development Environment (IDE) for use with all of Atmel's own brand AVR Tools including the AVRISP, STK500, JTAG ICE mk1 / mk2, ICE40 and ICE50. AVR Studio is freely distributed by Atmel and can be downloaded from the Atmel web site.  

AVR Studio 4 provides a project management tool, source file editor, chip simulator and in-circuit emulator interface for the powerful AVR 8-bit RISC family of microcontrollers.