According to the following, it's not really open-source (and more of a "gimmick"): http://hackaday.com/2011/08/03/microsofts-attempt-at-an-arduino-killer-feels

According to the following, it's not really open-source (and more of a "gimmick"): http://hackaday.com/2011/08/03/microsofts-attempt-at-an-arduino-killer-feels-like-a-gimmick/ http://hackaday.com/2011/08/03/microsofts-attempt-at-an-ardu...