Just thinking that VRPN might be a relatively easy way to support all those weird old 3D input devices that Touch used to support, along with weird new ones, without adding a new CHOP for each one. In a nutshell, VRPN acts as a server and passes on generic t[xyz],r[xyz] plus buttons, wheels, sliders etc.from each device that Touch would pick up via a socket.
as per the short discussion long ago with teflonjf…
viewtopic.php?f=4&t=2737&p=9648&hilit=vrpn#p9644
there are probably ways to set it up using sockets, OSC etc. (see links in the above referenced thread) but it would be nice to have its own native thing rather than homebrewing it.
I’d wager that there are a few Touch users connected to labs and other places with ancient SpaceMouse, Flock of Birds, iCube etc. that would still work (if you can find an old-school rs232 card?) if they could only talk.
(selfishly thinking of my dust-covered bucket of spacemice etc. that I just can’t bring myself to throw out after fishing them out of research-lab dumpsters a decade ago) 
Rod.