Our tiles were essentially USGS topo maps, generated by GIS on the backend. This pre-dates even IE's first vector stuff, so the only way to deliver things like

Our tiles were essentially USGS topo maps, generated by GIS on the backend. This pre-dates even IE's first vector stuff, so the only way to deliver things like this was images (with transparent .gif overlays for things like our trails and markers). The only two options available were pre-computing and storing, or generating on the fly. Drives were nowhere near big enough to store enough precomputed tiles to be useful. Machines weren't cheap enough to buy the sort of computing power (on our budget) to generate on the fly, since a handful of users could peg a machine. We might have been able to write our own fast, stripped down, GIS renderer to get costs down a bit. Instead, we took the 90s option of burning through our VC as quickly as possible and hitting the ground hard. It was a fun time.