http://www.angellabsllc.com
http://ecomotors.com
Angel Labs has a very old engine concept. Probably doomed to wankel status.
Not sure about the other design from EcoMotors. Looks very interesting. Submarine and some locomotive motors used that opposed piston tech, just not the opposed cylinder part.
The motors that were so reliable in subs, were never really popular in locomotives, they tended not to hold up in over the road use.