Source views: Source JSON(ish) on GitHub (VSCode)   Doc views: Document (&k=1.7.sec): Visual Print Technical: OpenParameters Xray
Except for the first RoR version, each of these dealt only with local sources, they imposed a hub. That creates obvious problems of confidentiality and robustness. Alan Littleford then did a version based on CouchDB distributed data model, which anticipates some of the benefits of blockchains.