This is genius: http://jcgt.org/published/0002/02/09/paper.pdf
An extremely simple approach on order independent transparency with good quality.
This is a blog post about it with some videos: http://casual-effects.blogspot.de/2014/03/weighted-blended-order-independent.html

Lite-C Tut. 1 Lite-C Tut. 2 Lite-C Tut. 3 (en)
Shader Tutorial (ger)

http://www.slindev.com