This was a MAJOR source for my History of SiliconGraphics series. Essentially no third party sources keep dates for SGI events, so their website's own press release archive inside the Wayback Machine allowed me to find dates for things that happened in quick succession. Think about a year like 1993. That year, SGI released the Indy, Indigo2, Onyx, and Challenge series. All of these are distinct products with distinct stories and their order of release really matters. Without the press releases in the Wayback machine, I would only have been able to find vague statements like "early 1993".
There is also an archived copy of the SGI website circa 1994 at employees.org: http://employees.org/~drich/SGI/SiliconSurf/
I spidered that site using HTTrack and copied it to the intranet webserver of a club at my school that has a lot of old computers for legacy software reasons. Looking at pictures of an Onyx rack on a 486 was probably what many of those here who were alive in the 90s experienced.