hi plp !!!
did you hear about Synapse?
it’s an open source nodal-based compositing software written in Qt and very easy to use.some of it’s features incluides custom nodes, rotoscoping, video editing…
however, it’s still WIP and would cool that you check it out and give it a feel.
here’s some cool videos showing Synapse in action!!!
visit…
http://code.google.com/p/vexx/
and let’s see what do you think!!