My company's RT info:
- RT 4.2.0
- MySQL 5.1.38
- CentOS 6.7
We have 11 IT users accessing daily to track/respond to requests. I've set up an "IT Viewer" role/group, with read-only permissions, so upper management can look at high-level reports or drill-down into individual tickets and see how we work. I've also set up (in addition to the 5 IT queues) 3 additional queues for other divisions. They have their own groups, permissions, users, etc., and RT does a splendid job of separation.
2009 Feb: Upgraded to 3.8.2.
2008-09-12: Just upgraded from RT 3.6.1 to 3.8.1... moved from an old piece of hardware to a VMware ESX server.
I'm LOVING 3.8.1, but I'm not sure which I love more -- the new look, new features, or the INCREDIBLY FAST performance on the new system. :D