Here at Linc's Lab, I run:
2 Sparcstation 20's - a mail/intranet webserver and it's backup running Debian
2 *old* Dell 2xxmhzmmx Pent's - mp3 server/file server/DNS/DHCP/NTP server and it's backup both running NetBSD
Pent 4xxmhz - gateway/router/webserver running Slackware 9.1
AMD Duron 950 - main workstation/print server running Slack 9.1
Pent 4xxmhz - secondary workstation/backup server(big disk space) running Slack 9.0
HP 9000/735 - HPUX test bed machine running HPUX 10.20
P90 Laptop - portable serial terminal mostly/checking out the latest NetBSD running, of course, NetBSD
P400 Laptop - portable workstation/TLLTS audio station running Slackware 9.0
Sparcstation voyager - portable workstation/sparc test install platform currently running SPLACK
SGI Octane - intranet webserver/IRIX testbed running IRIX
Then there are the ones I am not *currently* using but do use on occasion:
There's an Indy, 3 macs, 3 vaxen, a couple shoebox Sparcs, Digital Alphastation, and other odds and ends. I would love to get all this stuff runing all at once but need a bigger place to play