Audacity, a popular free audio editing software, has released version 4.0, introducing a redesigned interface and new ways to handle audio clips. This update, first announced in November 2024 with version 3.7.0, is now available for Windows, macOS, and Linux, alongside the existing 3.x version of the software. The new interface is built using the Qt framework, which allows the same code to run smoothly on all three operating systems. This update includes support for high-definition screens, light and dark modes, and automatic matching of system accent colors. Users can choose from different "Workspaces" — Modern, Classic, and Music — each offering a distinct layout that can be further customized by rearranging panels and toolbars. One of the major changes in version 4.0 is the improved handling of audio clips. Users can now select multiple clips at once to move, cut, or group them, even between mono and stereo tracks. A clip can be placed on top of another to replace the overlapping section, and a shortcut (the S key) allows users to quickly cut a track. Clip envelopes allow users to adjust volume or add fades without altering the original recording, continuing the non-destructive editing approach introduced in previous versions. Additionally, the playback head can be moved to any point on the timeline without shifting existing clips, making editing more flexible. Projects are now saved in a new .aup4 format, which preserves thumbnails and clip formatting data. While older .aup3 files can be opened in version 4.0, once a project is converted to the new format, it cannot be reverted. Some features from the previous version, Audacity 3, are not included in 4.0. These include timeline tracks, Note/MIDI tracks, the Mixer, the Macro Manager and its script pipeline, support for VAMP and LADSPA plugins, and the Play-at-speed function. The developers, Muse Group, have stated that they are working to reintegrate some of these features in future updates. Despite these omissions, Audacity 4.0 remains free and open-source, licensed under the GNU General Public License version 3 (GPL v3). The update aims to modernize the software's interface and improve usability across different operating systems, while maintaining the core functionality that has made Audacity a go-to tool for audio editing. The new features and interface enhancements are expected to appeal to both new users and experienced editors looking for a more streamlined and visually consistent experience.