For 6.3.1, it says you should download if you are an early adopter. What does that mean?
Changes in the first and second numbers in the version number indicate big changes in the package, things that provide new features but that may need more “fine tuning” and bug fixing. The third number in the version number indicates bug fix releases and generally speaking a large third number indicates a more “stable” release.
Now we have 6.2.7 in the “still” branch, that’s considered “stable,” and 6.3.1 in the “fresh” branch, that’s considered “probably less stable.” People that need stability are encouraged to use the “still” branch while people that want to test the new features and are willing to face (and report) eventual bugs, i.e., the “early adopters,” can use 6.3.1.