The most recent "stable" version of Elgg is the one from the main page http://elgg.org/ which is 1.8.19 at the moment.

Doxygen-generated reference uses names of branches, so if you see Version master, that means master branch on github and if you see 1.8, it's 1.8 branch (which is NOT exactly the same as last released version). Either way that's only a bunch of html generated from doc blocks, so configuring your IDE to correctly recognize project comments may be more useful for you. I for one, use reference ONLY to point people to the function they can use. I don't remember ever using it during development. But no harm in having it.

Reference does miss branches after our recent reorganization, I'll fix it in few minutes, generally we follow semver now:

• 1.9 - 1.9.x development (bugfixes only, features are frozen already)
• 1.x - features that are backward compatible
• master - backward incompatible changes

Branches 1.9 and 1.x are missing from reference currently.

"Sphinx documentation" is just a source for human readable documentation that is to replace old wiki. It's automatically updated on http://learn.elgg.org/ and is built from several branches independently.

Edit:

I've added new branches to reference.elgg.org, which makes following a full list of versions:

• http://reference.elgg.org/1.5/
• http://reference.elgg.org/1.6/
• http://reference.elgg.org/1.7/
• http://reference.elgg.org/1.8/
• http://reference.elgg.org/1.9/
• http://reference.elgg.org/1.x/
• http://reference.elgg.org/master/
• and http://reference.elgg.org/ is displaying version 1.8

Thank you for your work, Pawel.
 

Now with peace of mind, i know that "master",

http://reference.elgg.org/master/index.html,

currently means "1.9.0-rc.6".
 

Yes, above link is important to start, and grep-on-source-code is important to follow.
 

Konstantin.

I'm really good friends with the original developer :)

Send me a PM.