Gestures not working

I just finished a vanilla as possible notebook hack, but I could not get gestures working. Why are they not working?

Is it a technical issue like non-apple touchpads do not support tracking four finger tips at a time? Is it a manpower issue? Like no one wanted to implement it, had time to do it? Or is it a issue of fragmentation? Like, a solution would work for some people but never for all since the trackpads are too different?

I am motivated to start some kind of project to get gestures working for the maturity of users. But I have not started gather knowledge, so if someone has more experience with touchpad driver development or apple gestures etc. it would be nice to get some hints/ideas for starting points (existing open source kext and solutions).

Or maybe it could work and I just did not find out how?