[MonoDevelop] Version confusion

[Matt Calder]

Hi,

I recently installed MD from the source on github, branch "master".
When I run Help-About I see "Version 2.8 Alpha 1 (2.7)". The recent
announcement was that "The MonoDevelop team is proud to announce the
release of MonoDevelop 2.6
Release Candidate 1 (2.5.93).". I see that on github there is a branch
2.5.93, and a branch 2.6.

My questions are: between the branches "master", "2.5.93", and "2.6"
what are the main differences, and which is to be preferred (and why)?
And additionally, if someone could give some background on the
plethora of version numbers that seem to be floating about (2.5.x,
2.6, 2.7, and 2.8), it would be very helpful.

Thanks,

Matt