One of the very first results on google is this
GitHub - jwiegley/org-mode: This is a very old fork of Org-mode, but it's ... https://github.com/jwiegley/org-mode
but I don't think that's the one I'm after.
Update: When I said "on the web" I meant browsable on the web. So using web browser I can
- see how active the repo is (eg. GitHub shows this)
- see how a file has changed over the years
- view README in browser
I appreciate Phils answer, but doing git clone or looking at auto generated org manuals or downloading tar.gz1 or zip1 on the web isn't what I was looking for.