LMS which version to use? 7.7.x 7.8.x 7.9.x

Hi

I've been using the 7.7.X branch for some time now on my Windows Server (WHS 2011) which is a HP Proliant N40L Microserver.

Looking at the wiki page here: http://wiki.slimdevices.com/index.php/Nightly_Builds

I see there are also 7.8.x and 7.9.x branches, why so many different versions?

Which one should I be using, what would you recommend?

Thanks