GIMP 2.99.6 is another development release on the road to a big GIMP 3.0 release with a graphical interface based on GTK 3, a brand new API, a new extension format, Wayland support, year 2038+ compatibility, multi-layer selection and much more. It may be worth a try if you want to know what GIMP 3.0 will be like, but it is nowhere near ready to replace the stable GIMP 2.10.xx branch.
