Document building and zoning data systems

[jpvelez]

It would be extremely useful to understand the internals of City systems that touch on buildings and zoning. Specifically, whatever systems are powering the following websites:

• Whatever system(s) runs building permitting and code enforcement. (Appear to be Infor Hansen, according to this document.)
• Building data warehouse
• Zoning map Probably some kind of ESRI system.
• Vacant building registry

There are lots of fields exposed across these systems that are not available in any of the relevant open datasets - building footprints, permits, violations, and the like - and it would be great to understand the data / software universe they come from.