foobar2000

foobar2000 (often abbreviated as fb2k or f2k) is a freeware audio player for Microsoft Windows, iOS, Android, macOS, and formerly Windows Phone, developed by Peter Pawłowski. It has a modular design, which provides user flexibility in configuration and customization. Standard "skin" elements can be individually augmented or replaced with different dials, buttons, and visualizers. foobar2000 offers third-party user interface modifications through a software development kit (SDK).

foobar2000 supports many audio file formats, has many features for organizing metadata, files, and folders, and has a converter interface for use with command line encoders. To maximize audio fidelity in cases where resampling or downscaling in bit depth is required, it provides noise shaping and dithering. There are a number of official and third-party components which add many additional features. The core is closed source, whereas the SDK is licensed under the Three-Clause BSD license.