Skeleton tracking without calibration (psi pose)

IN the past i worked with ofxOpenNI and ofxMsKinect.

The best way to get the skeleton data fast without the Psi pose its by using the KinectSDK with openframeworks.
Maybe you can use a PC for the skeleton tracking and send the data to your mac app using OSC. I rememberd it worked quite well with almost no delay.
https://github.com/simonhr/ofxMSKinect