Openpilot

http://www.rcgroups.com/forums/showthread.php?t=1454007#post18481551

http://diydrones.com/profiles/blogs/openpilot-open-souce-uav?id=705844%3ABlogPost%3A446140&page=2#comments

hrdware distrib
http://flaps.chebuzz.com/

V-tail provides best Yaw control
http://forums.openpilot.org/topic/7304-my-v-tail-quad/

http://forums.openpilot.org/topic/6915-work-in-progress/

http://forums.openpilot.org/topic/5592-y4-layout/page__hl__vtail__st__40 Six motors + two for v-tail - Octacopter

open pilot

 * http://www.rcgroups.com/forums/showthread.php?t=1199346 OPEN pilot
 * http://openpilot.org/ Probably the best opensource solution at the moment
 * http://www.google.com/patents?id=krGRAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false Patents on UAV Kalman filtering

As we are a GPL project, code reuse is a major asset that we can leverage both for ideas and to re-use code directly. There are a couple of projects we have already used or plan to use code from and this speeds up development as well reducing bugs because we are using known good code. Of course we can only use code where the license allows, for example GPL, LGPL and BSD licensed projects. Examples are Booz from Paparazzi and UAVX from Professor Egan and Dr. Jim. Of course this is a two way street, they can also share code we create as well so everyone wins.

tri-copter
http://www.youtube.com/watch?v=6tycXLZgO-Y&feature=youtu.be&a

http://www.rcHobbyHelicopter.com

nano frame
http://www.eyefly.info/

http://forums.openpilot.org/topic/6775-quadrixette-nano-micro-frame-especially-made-for-the-open-pilot-copter-control/page__st__180