The purpose of this repository is to analyze the data about ESRI coordinate systems in their own repo at https://github.com/Esri/projection-engine-db-doc/
To get this, there are available a couple of html files that parse the json files from ESRI to display that information. All the information about the CRSs are read at runtime from their repo, so it is updated automatically.
For more detailed information, please refer to ESRI repository or documentation.
If you have another useful "query" to include here, do not hesitate to contact me.
This is list of all the deprecated CRS in ESRI (projected, geographic and vertical), that have an equivalent in EPSG. (AFAIK, that is a reason enough to deprecate a CRS in ESRI: having an equivalent in EPSG).
https://jjimenezshaw.github.io/Esri-codes-analyzer/deprecated.html
This is just a list of all non-deprecated CRS, with name and description.
https://jjimenezshaw.github.io/Esri-codes-analyzer/not-deprecated-esri.html