When you want to find out who's using up all the licenses, you can run lmstat -a do find out.

Specifically, with Mac COMSOL, I do:

> cd /Applications/COMSOL43a/license

> maci64/lmstat -a -c license.dat

Users of COMSOL:  (Total of 5 licenses issued;  Total of 1 license in use)

  "COMSOL" v4.3, vendor: LMCOMSOL

  floating license

    dmassey c22042.local (v4.3) (ancha/1718 1074), start Thu 12/13 18:26

etc.