Official technology stack documentation by Trello: http://www.bestvendor.com/lists/building-and-maintaining-tre...

OpenSource clones: https://github.com/oo7ph/Trello-Clone

https://github.com/chris-ramon/minitrello

https://github.com/GraemeF/rello

https://github.com/commoncode/mello

https://github.com/swizard/brello

https://github.com/guysherman/itemlist

https://github.com/philipposgate/mello

https://github.com/ichiro101/jirello

https://github.com/brendanheywood/ghello

https://github.com/jluna79/pillo

https://github.com/jiewmeng/Tickle

https://github.com/edulix/kanllo

https://github.com/StrictlyBusiness/Mello