Quod Libet is very scalable, able to handle libraries with tens of thousands of songs. It provides a full feature set including support for Unicode, regular expression searching, key bindings to multimedia keys, fast but powerful tag editing, and a variety of plugins.
Quod Libet is available on most Linux distributions, macOS and Windows, requiring only PyGObject, Python, and an Open Sound System (OSS), ALSAorJACK compatible audio device. The XFCE desktop ISO image provided by the Debian project installs Quod Libet as the default audio player.[5]
Quod Libet's tag-editing and library organization features are also available through a standalone program, Ex Falso, which is based on the same code and libraries as Quod Libet.
Changes to multiple files at once, even if files are in different formats
Ability to tag files based on filenames with fully configurable formats
Customizable renaming of files based on their tags and a user-supplied format
Human readable tag references, e.g. <artist>or<title> rather than %aor%t, with support for "if not-null x else y" logic (e.g. <albumartist|albumartist|artist>)
Progressive search - the library is filtered as searches are typed
Queries support boolean logic, numerical / date-based expressions, regular expressions, and synthetic tags, that are derived internally (e.g. play count, rating, inclusion in a playlist).
Playlists with integration throughout the player
Paned browser, using any fully customizable tags (e.g. genre, date, album artist...), allowing the user to [drill down] through their library as they prefer
