Master:
This branch is what we could consider "stable" and is the officially supported firmware. This means if you are having a problem, we can offer help via tickets/emails etc... It is what we want everyone to use.
Dev:
This is where we are testing fixes/features/bug workarounds etc. This is NOT considered stable, and we would not want anyone using it unless they feel comfortable considering themselves a "beta tester" kind of person. There will be times that someone in support may ask you to try this branch for help in solving your issues, but unless someone from SeeMeCNC DIRECTLY tells you to use this branch, please stay on the master branch. The reason for this is to eliminate variables in troubleshooting anything.
Unstable:
You read it right. It says UNSTABLE. This is our 'playground' that has bad stuff in it. Not necessarily, but for all intents and purposes, it's full of smoke and mirrors and things that will break your printer
If you use this branch, there is absolutely no support. Please "enter at your own risk"