Learn more about ORCA and FALCOR

ORCA and FALCOR work hand in hand and are a great asset for anyone working on real-time rendering.
Find out more about these industry initiatives :

What is the main differences between https://github.com/nvpro-pipeline/pipeline and Falcor? (I’ve not used either, but have had nvpro-pipeline on my to-look-at list for a while now)

I don’t know nvpro-pipeline, so I can’t comment on it.
We’ve been using Falcor for research in the last 2 years with around 25 published papers, so we know it’s stable and will make you very productive.

Is there any documentation on Falcor? It looks very interesting. Or any open source projects using it?

We are working on documentation. Not sure who is using it.
You can get it from https://github.com/NVIDIAGameWorks/Falcor. There are a bunch of samples included.