AVR-Dopper USB AVR programmer A Firmware-Only USB Driver for Atmel AVR Microcontrollers

PROTTOSS AVR USB Programmer (Scematic, firmware, drivers for Win2k Vista/XP32 Vista/XP64)

c8051f340 USB Firmware Programmer s Guide

USBasp is a USB in-circuit programmer for Atmel AVR controllers. It simply consists of an ATMega48 or an ATMega8 and a couple of passive components. The programmer uses a firmware-only USB driver, no special USB controller is needed.