5.1.x are the stable “release” versions.
5.99 is the unstable, nightly development version of what will be 6.0.
5.99 has a lot of nice new features, but also some caveats. See Is it a good idea to use a nightly build version?
5.1.x are the stable “release” versions.
5.99 is the unstable, nightly development version of what will be 6.0.
5.99 has a lot of nice new features, but also some caveats. See Is it a good idea to use a nightly build version?