With the release of WebKitGTK 2.40.0, WebKitGTK now finally provides a stable API and ABI for GTK 4 applications. The following API versions are provided:
- webkit2gtk-4.0: this API version uses GTK 3 and libsoup 2. It is obsolete and users should immediately port to webkit2gtk-4.1. To get this with WebKitGTK 2.40, build with
-DPORT=GTK -DUSE_SOUP2=ON. - webkit2gtk-4.1: this API version uses GTK 3 and libsoup 3. It contains no other changes from webkit2gtk-4.0 besides the libsoup version. With WebKitGTK 2.40, this is the default API version that you get when you build with
-DPORT=GTK. (In 2.42, this might require a different flag, e.g.-DUSE_GTK3=ON, which does not exist yet.) - webkitgtk-6.0: this API version uses GTK 4 and libsoup 3. To get this with WebKitGTK 2.40, build with
-DPORT=GTK -DUSE_GTK4=ON. (In 2.42, this might become the default API version.)
WebKitGTK 2.38 had a different GTK 4 API version, webkit2gtk-5.0. This was an unstable/development API version and it is gone in 2.40, so applications using it will break. Fortunately, that should be very few applications. If your operating system ships GNOME 42, or any older version, or the new GNOME 44, then no applications use webkit2gtk-5.0 and you have no extra work to do. But for operating systems that ship GNOME 43, webkit2gtk-5.0 is used by gnome-builder, gnome-initial-setup, and evolution-data-server:
- For evolution-data-server 3.46, use this patch which applies on evolution-data-server 3.46.4.
- For gnome-initial-setup 43, use this patch which applies on gnome-initial-setup 43.2. (Update: for your convenience, this patch will be included in gnome-initial-setup 43.3.)
- For gnome-builder 43, all required changes are present in version 43.7.
Remember, patching is only needed for GNOME 43. Other versions of GNOME will have no problems with WebKitGTK 2.40.
There is no proper online documentation yet, but in the meantime you can view the markdown source for the migration guide to help you with porting your applications. Although the API is now stable and it is close to feature parity with the GTK 3 version, there are some problems to be aware of:
- No support for accessibility. The GTK and WebKitGTK developers are collaborating on a plan to fix this, and I hope this will be ready for WebKitGTK 2.42.
- Multiple NVIDIA proprietary graphics driver users report that it doesn’t work at all. Nobody currently plans to work on this. The WebKitGTK developers do not use NVIDIA graphics, and it will have to be debugged by somebody who does.
- Various smaller regressions here and there. The GTK 4 version is almost as stable as GTK 3, and now is a good time to start using it. As with any interesting new software, there is still some work to do.
Big thanks to everyone who helped make this possible.