It looks like the pile includes an APC AP7921 networked, monitored PDU. If so, you should definitely take it. It's worth about $200. https://www.amazon.com/dp/B0000AAAV0
The Sun Fire V20z was released back in 2004, so it's far too old to be of practical use.
The IBM xSeries 336 is a couple years newer, but it's still far too old.
The big APC UPS on the floor may potentially be revived with new batteries, but may require installation by a registered electrician due to the large current required. You're better off with a smaller unit, in the 1500-2000 VA range.
That's about all I can recognise from these pics.