Yep. Last commit 5 years ago, not included by default on distro's or kernels, build-from-source-and-hope... ;-)

The kinect1 appears to be "OOTB-ish" at least on ubuntu: https://launchpad.net/ubuntu/+source/libfreenect

...so just an advisory that for casual purposes a Kinect1 is going to be better than a Kinect2.