RepRap: Blog

I recently acquired and built a Freeduino kit from nkcelectronics. The freeduino board is a clone of the Arduino and is 100% compatible, right down to the pin placements. It was a painless build, and the board worked right away. If you want to have a machine where you've built all the boards yourself, or you want to save $10 and buy a kit, this board is for you. Or, if you just want a board that is as free as free can get.

From the Freeduino website:

Freeduino is a collaborative open-source project to replicate and publish Arduino-compatible hardware files. The Freeduino Eagle SCH, BRD and Gerber production files allow users to create boards that are 100% functionally, electrically and physically compatible with Arduino hardware.