Mixxx, the free and open-source DJ software, released new major 2.5.0 version today!
The new release now uses Qt6 by default for its user interface, offering improved performance and enhanced compatibility with modern systems. Qt5 is still supported, but will be removed in the next 2.6 release series.
Probably due to this change, Ubuntu 20.04 is no longer officially supported, though user can choose to use the Flatpak package run in sandbox environment.