Cacher is the code snippet organizer for pro developers

Python Distance calculation:
https://www.derivative.ca/forum/viewtopic.php?f=27&t=7184
https://stackoverflow.com/questions/21369449/how-to-calculate-the-distance-between-two-points-using-return-methods-in-python

GroupSop technique
http://www.derivative.ca/Forum/viewtopic.php?f=17&t=4663&p=27466#p27466

https://www.derivative.ca/wiki088/index.php?title=Spring_SOP
http://www.derivative.ca/forum/viewtopic.php?f=4&t=6560

- Collision Node Xpresso -
http://lesterbanks.com/2015/04/understanding-the-xpresso-collision-node/
-> also talks about re-Creating it in Python