Gajim is currently migrating from GTK3 to GTK4. 🔧 GTK is Gajim's user interface toolkit. It provides building blocks, like windows, buttons and labels. 🧩
Version 4 of this toolkit brings performance improvements to Gajim, e.g. faster rendering of user interface elements. 💨
Additionally, switching to GTK4 allows Gajim to use newer widgets, like nice drop downs.
Here is a quick peek at a new group chat "@ mention" widget. 😎
Stay tuned! 
The GTK Project - A free and open-source cross-platform widget toolkit
GTK is a free and open-source cross-platform widget toolkit for creating graphical user interfaces.The GTK Team