Most exciting with GTK 4.2 is its new “NGL” OpenGL renderer being the default across Linux, macOS, and Windows platforms. The NGL renderer is the default across those major platforms while the old OpenGL renderer is still being maintained for the time being and can be enabled via an environment variable override (GSK_RENDERER=gl) for helping to weed out any remaining issues with NGL.
The GTK4 NGL renderer should allow for even better performance across mobile and desktop systems. The performance should already be quite good while the developers continue working on optimizing for even more features and performance moving forward.
Also on the performance front, GTK 4.2 features “performance improvements all across the board, from GLSL shaders used to render our content, to the accessibility objects created on demand instead of upfront.”
GTK 4.2 is also shipping with input handling improvements, continued work on portability and build system features, improving the GTK4 documentation, better Wayland input method protocol support, improved scrolling performance, enhancements to the sub-pixel positioning of text, and more.
More of the highlights on GTK 4.2 can be found via the GTK.org blog.