I don't know if they're still using it but around 2010 or so a client from the early 2000s got in touch because the UPS they were using for their SCO Unix + serial terminals server had failed and they wanted to replace it. I was amazed that they were still using it. I was even more amazed that the APC UPS they were going to replace the old one with... had a new version of the SCO UPS Monitoring application that they used to automatically do a clean shut down of the server if the power was out too long. Got them all set up and everything kept humming along.