This started out as a static HTML file, being used by some developers at my current employer to document "domain terminology" relevant to products we're building.
Soon it became too much work to update the items in the HTML manually, so I added a JavaScript-based editor. It relies on a tiny Node.js server to write changes back to the HTML file.
Not as user-friendly as a "normal" web-based application, but it does mean we can keep the HTML file under version control and follow our normal development process for making/tracking changes.
http://www.catb.org/jargon/html/