You can get Nxt forging algo in slighlty simplified form in my blog http://chepurnoy.org/blog/2014/10/inside-a-proof-of-stake-cryptocurrency-part-2/ . And I'm going to investigate Qora's forging algo(got no detailed view from first investigation). I can even publish a blog on that if it's interesting, and make executable simulation of Qora forging process(I already made that for Nxt https://github.com/ConsensusResearch/ForgingSimulation )