xCrowd
On July 2nd, 2013, xCrowd announced their intention to produce a custom Bitcoin mining ASIC.[1][2]
Although not formally canceled, no substantial post was made to its announcement thread by xCrowd since August 26th, 2013.[3]
As of June 6th, 2014, the original BitcoinTalk Forum account used by xCrowd appears to be in use by a different person, based on the changes in writing style and interests.[4]