A recent search on Yahoo for "supermac" found 438 pages (not including this one). Not all of them are worth visiting. Trust me. In fact, most of them have nothing to do with SuperMac computers. Others do, but are inacurate or incomplete to the point that I can't personally recommend them. There are many others which sell memory or other spare parts for the SuperMacs, but as I intend to keep this site entirely non-commercial, I won't mention them here.
An outstanding, community-driven archive of legacy classic Mac software, including a good range of UCC/SuperMac downloads. If you download anything of use to you from there, please consider donating to Macintosh Repository to help support their continued awesome work.
This is the biggie. If there's only one site on the web for ongoing SuperMac support and advice, this is it. (If there are two sites, then I like to think SuperMac Insider is the other.) The SuperMacs user group mailing list alone makes it worth the trip.
A great profile page of the ultra-rare SuperMac J710, which was shown at MacWorld '98 but never sold. This was actually my own personal machine, which contained the even more rare G3 ZIF upgrade. I donated it to a collector/enthusiast, who passed it on to its current owner back in 2012.
A few ancient distractions on products from the original SuperMac Technology, but for the most part, a great collection of Mac clone time capsules. Enter "supermac" in the search field, and enjoy.
A mildly-entertaining look back at the Mac price wars of early 1997 -- much sound and fury signifying the loss of profits for all and the growth of market share for... well, not the Mac OS. We can laugh about it now.