Hi Ralph and everybody,
OK, we don't use /opt for things particular to certain groups but /<something>_sw/<group> trees, where EPICS has its own
/<something>_sw/epics tree.
But, those trees are usually owned by a member of the group and group-writable for the source location, but usually not for the install location (but the parent directories are so that a member of the group can create a new version. Having versions in install trees (of our own software) makes it easy to go back to a previous version). - Our /opt contains directories named
Adobe/ google/ rh/ sun/
i.e. nothing particular to any group
(the sun directory is rather old, even for here, I'm not sure we still have a solaris machine - I know why we kept one around but it may have gone with the equipment for which we kept it around)
What I'm trying to get at here is that there may be space outside of real system space (that I wouldn't write into as long as I can help it), /opt (which I still consider close to system space) and users' home space that can still be group specific - and isn't necessarily owned by root, so that members of the same group can write to it without using sudo.
If you don't have such things at your site, maybe ask your systems people to add it, and to create groups appropriate to write to that space.
(Wasn't my idea, but I quite like it that way)