This is an LV2 and LADSPA port of TF Chorus by TraumFlug. The great, unique chorus effect was found in the Armstrong package of an old PPA.
Any information about this plugin seems to have disappeared from the internets. There was no license, except that it is implied to be "free, open source software" (see src/tfcho_orig.cpp, the original source) and that the rest of Armstrong is released under GPLv2. For now let's say this port is under the same license as the original, whatever it may be.
~ grejppi