Beginning a slow project of updating the docs about the IndieAuth spec, today I started by updating a few pages on the wiki. Right now, most of the docs about IndieAuth (the spec), and how to use it, live across a variety of pages on the wiki, grouped together at https://indieweb.org/Category:IndieAuth.
My goal with the spec IndieAuth is to make it an extension of the OAuth 2.0 spec. It has always been based off of the OAuth 2.0 spec, but I've never written it up properly as an extension. It's always been just a series of how-to guides. Additionally, I had originally started by specifying all of the responses being form-encoded responses, whereas the OAuth 2.0 spec says all responses must be JSON format. I've been slowly converting my various apps that use IndieAuth to support both, based on the HTTP Accept header, although I haven't publicized this much yet.
Today's project was updating the existing IndieAuth documentation on the wiki to explicitly include the JSON versions as a valid response format.
Eventually I hope to write up IndieAuth as a formal extension to OAuth 2.0, in the same format that something like the Device Flow is an extension.