One of the machines I use to build SPARC packages for Tribblix is an old SunBlade 2000.
It's 18 years old, and is still going strong. Sun built machines like tanks, and this has outlasted the W2100z (Metropolis) that replaced it, and the Ultra 20 M2 that replaced that, and the Dell that replaced that.
It's had an interesting history. I used to work for the MRC, and our department used Sun desktops because they were the best value. Next to no maintenance costs, just worked, never failed, and were compatible with the server fleet. And having good machines more than paid back the extra upfront investment. (People are really expensive - giving them better equipment is very quickly rewarded through extra productivity.)
That compatibility gave us a couple of advantages. One was that we could simply chuck the desktops into the compute farm when they weren't being used, to give us extra power. The other was that when we turned up one morning to find 80% of our servers missing, we simply rounded up a bunch of desktops and promoted them, restoring full service within a couple of hours.
When the department was shut down all the computers were dispersed to other places. Anything over 3 years old had depreciated as an asset, and those were just given away. The SB2000 wasn't quite, but a research group went off to another university taking a full rack of gear and some of the desktops, found they weren't given anything like as much space as they expected, and asked me to keep the SB2000 in exchange for helping out with advice if they had a problem.
The snag with a SunBlade 2000 is that it's both huge and heavy. The domestic authorities weren't terribly enthusiastic when I came home with it and a pair of massive monitors.
The SB2000 ended up following me to my next job, where it was used for patch testing and then as a graphical station in the 2nd datacenter.
And it followed me to the job after, too. They gave me an entry-level SunBlade 1500, I brought in the SB2000 and it's 2 22-inch Sony CRTs.
After a while, we upgraded to Ultra 20M2 workstations. Which released the monster, initially again as a patch test box.
At around this time we were replacing production storage, which was a load of Sun fiber arrays hooked up to V880s, with either SAS raid arrays connected to X4200M2s, or thumpers for bulk image data. Which meant we had a number of random fiber arrays kicking around doing nothing.
And then someone shows up with an urgent project. They need to store and serve a pile of extra data, and it had been forgotten when the budget was put together. Could we help them out?
Half an hour later I had found some QLogic cards in the storeroom, borrowed some fibre cables from networking, shoved the cards in the free slots in the SB2000, hooked up the arrays, told ZFS to sort everything out, and we had a couple of terabytes of storage ready for the project.
It was actually a huge success and worked really well. Some time later a VP from the States was visiting and saw this Heath Robinson contraption we had put together. They were a little bit shocked (to put it mildly) to discover that a mission-critical customer-facing project worth millions of dollars was held together by a pile of refurbished rubbish and a member of staff's cast-offs; shortly thereafter the proper funding for the project magically appeared.
After changing jobs again it came home. By this time the kids were off to University and I had a decent amount of space for a home office, so it could stay. It immediately had Tribblix loaded on it and has been used once or twice a week ever since. And it might be a little slower than a modern machine, but it's definitely viable, and it's still showing no signs of shuffling off this mortal coil.