BOARDS :
Arduino
http://www.arduino.cc/
Maple
http://www.leaflabs.com/
Netduino
http://www.netduino.com/
Fez Panda / Spider / Domino
http://www.ghielectronics.com/catalog/
Teensy(++)
http://www.pjrc.com/teensy/
TI MSP430 Launchpad
http://e2e.ti.com/group/msp430launchpad/w/default.aspx
Duinomite
http://www.duinomite.com/
STM32 Value Discovery (+ several variants)
http://www.st.com/internet/evalboard/product/250863.jsp
CHIPS :
PIC
http://www.microchip.com/stellent/idcpl ... odeId=2551
Atmel
http://www.atmel.com/products/microcont ... fault.aspx
OTHER :
Raspberry Pi
http://www.raspberrypi.org/