The SPARCstation platform was a popular Unix workstation in the '80s and '90s in education and corporations. The "pizza box" dimensions fit on the desktop with a big monitor on top and packs a dense load of electronics inside with keyboard and mouse 'round front. As with most of my exhibits, I ran mine headless because I don't have a lot of space for monitors.
I bought my first SPARCstation 20 (SS20) at the local Goodwill ComputerWorks. At some point I upgraded its Sun single CPU card with a ROSS CPU accelerator card that provided a pair of 125 MHz HyperSPARC RT625 32-bit CPUs with on-board cache-controllers on one single-width M-bus card.
And because I was so nutty about symmetric multiprocessing (SMP) before multi-core AMD and Intel x86 chips made it commonplace, I also bought a 4-CPU SPARCserver 20 (also SS20 and labelled SPARCstation on the case) on eBay. It populated both M-bus slots with two 50 MHz SuperSPARC 390Z55s and their cache controller chips. With four big chips per card, the width took over the space of the S-bus slot next to it and was covered with a huge heatsink. The SPARCserver line provided small airflow improvements such as more open space on the left side exhaust vents.
Improvements over the earlier SS10 include wide SCSI interfaces, higher density/speed DRAM SIMM cards, a compact laptop-style CD-ROM drive and on-board audio.
Unfortunately, however, the Linux kernel dropped support for the sparc32 architecture in 2007. Eventually I moved the running SSs to NetBSD.