MPlayer is a free and open-source media player that supports a wide range of audio and video formats. It is known for its versatility and ability to play files from various sources, including local storage and streaming services. MPlayer is available on multiple operating systems, including Windows, macOS, and Linux. The player features a simple command-line interface, but it also supports graphical user interfaces through front-end applications. Users can customize playback options and utilize advanced features like subtitle support and video filtering. MPlayer is popular among users who appreciate its lightweight design and extensive format compatibility.