Audacity 4.0 beta lets you test its new (nicer) Qt interface
Summary
Audacity 4.0 beta introduces a Qt-based UI atop the existing engine, marking a major visual revamp. The beta adds spectral editing, a redesigned envelope tool, multi-project support, cross-platform plugin compatibility, and built-in cloud saving, with caveats about stability. Audacity 3.x project compatibility exists but some 3.x features may be dropped; testing recommended for users who can tolerate potential crashes.