MacAmp
MacAmp is an early GUI-based MP3 Media [player software|audio player], first released on April 13, 1997, for the Macintosh by Dmitry Boldyrev of Nullsoft. Its MP3 decoding capability was based on the PlayMedia Systems AMP MPEG-2, Layers 1, 2 and 3 decoder.
By 1999, MacAmp was cited as a "premier MP3 player" and the most popular MP3 player for the Macintosh.
In September 1999, a revamped version of MacAmp was released under the name "Macast".