GNOME's GTK Developers Come Up With A Plan For GTK+ 4

At a GTK+ hackfest this week the developers have come up with a new plan for delivering major releases of the GTK+ tool-kit every two years, e.g. GTK4, GTK5, GTK6, etc.

GTK+ developers have acknowledged GTK3 has less-than-perfect API stability and are looking to improve their development process and allow GTK+ to better evolve. They are now planning to do releases of new major versions of GTK (GTK4, GTK5, GTK6, etc) every two years. These major new GTK versions will be fully parallel-installable to allow multiple GTK versions on the same system.

As part of this more rapid evolution of GTK, the API will not initially be stable. Between say GTK 4.0 and GTK 4.2, the API can break, but around the GTK x.6 release is when they would call themselves API/ABI stable. Thus the libraries will be versioned accordingly for these minor GTK revisions that can break the API.

Basically, the GTK+ updates that are released not on a two-year cadence will be considered unstable while the the two-year releases that will be timed with major Linux distribution releases will be deemed what's really hardened.

More details on the early GTK4 planning via this blog post.