It looks like the intel driver is blacklisted :-(. So I can only do webgl.
I have to install newer mesa libraries from the glasenhard ppa:
sudo apt-add-repository ppa:glasen/intel-driver
Then in firefox I can enable mesa (setting the values in about:config):
webgl.force-enabled true
webgl.osmesalib /usr/lib/libOSMesa.so.6.5.3
This allows me to see webgl examples. But so far I don't get the 3d inspector to run.