We were writing web based GIS in 1996, using ESRI&#x27;s MapObjects IMS. Tiling, projections, yes these were solved problems by then using available commercial software.<p>We were storing data in Oracle or DB&#x2F;2 with ESRI&#x27;s SDE sitting on top, because at that time no mainstream RDBMS had spatial types.<p>I don&#x27;t recall if SDE supported SQL Server back then. That aside, you could have built TerraServer with COTS tech in 1997.<p>TerraServer was impressive due to being publically available. Nothing we built at the time was available to the public as far as I remember. But it existed.<p>And that&#x27;s just web based stuff, which really is the easy part. Large scale GIS had been around for decades prior.