USBasp is a USB in-circuit programmer for Atmel AVR controllers  
It simply consists of an ATMega88 or an ATMega8 and a couple of passive components. The programmer uses a firmware-only USB driver, no special USB controller is needed.
Features
Works under multiple platforms. Linux, Mac OS X and Windows are tested.
No special controllers or smd components are needed.
Programming speed is up to 5kBytes/sec.
SCK option to support targets with low clock speed (< 1,5MHz).
 
Supported Software: AVRDude 5.2 or higher
Supported Microcontrollers:
Mega Series
ATmega8 ATmega8A ATmega48 ATmega48A ATmega48P
ATmega48PA ATmega88 ATmega88A ATmega88P ATmega88PA
ATmega168 ATmega168A ATmega168P ATmega168PA ATmega328
ATmega328P ATmega103 ATmega128 ATmega128P ATmega1280
ATmega1281 ATmega16 ATmega16A ATmega161 ATmega162
ATmega163 ATmega164 ATmega164A ATmega164P ATmega164PA
ATmega169 ATmega169A ATmega169P ATmega169PA ATmega2560
ATmega2561 ATmega32 ATmega32A ATmega324 ATmega324A
ATmega324P ATmega324PA ATmega329 ATmega329A ATmega329P
ATmega329PA ATmega3290 ATmega3290A ATmega3290P ATmega64
ATmega64A ATmega640 ATmega644 ATmega644A ATmega644P
ATmega644PA ATmega649 ATmega649A ATmega649P ATmega6490
ATmega6490A ATmega6490P ATmega8515 ATmega8535

Tiny Series
ATtiny12 ATtiny13 ATtiny13A ATtiny15 ATtiny25
ATtiny26 ATtiny45 ATtiny85 ATtiny2313 ATtiny2313A
Classic Series
AT90S1200 AT90S2313 AT90S2333 AT90S2343 AT90S4414
AT90S4433 AT90S4434 AT90S8515
AT90S8535
CAN Series
AT90CAN128
PWM Series
AT90PWM2 AT90PWM3
 
How to use it?
1. Plug in USBasp
2. Download Zadig from [zadig. akeo. ie]
3. Start zadig
4. Options > List all devices
5. Select USBasp from the drop down menu
6. Select libusbK(v3.0.7.0) driver
7. Click Install