ProTracker is a popular freeware tracker created by Lars Hamre, Anders Hamre, Sven Vahsen and Rune Johnsrud for the Amiga platform. It is amongst the programs that first allowed for widespread creation of music without studio equipment. It was popular for amateurs and professionals alike, and ProTracker amongst others set a standard for the MOD fileformat.
There's ongoing effort to rewrite ProTracker at SourceForge for modern platforms. It is currently on beta stage.
Protracker allows the user to create sequences of notes called "patterns", which are chained together to form a complete song. Music created in Protracker uses the MOD file format.
It was initially developed for the Amiga line of computers, but was later made available for other contemporary platforms such as the Atari ST.
Currently, there are two version of Protracker for Atari available.
In addition to the basic features provided by Ultimate Soundtracker and NoiseTracker, Protracker came equipped with a built-in sample editor and a keyboard split function to assign multiple instruments to different regions of the keyboard. Later versions also extended the MOD format by increasing the maximum number of patterns from 64 to 99.
Protracker is capable of playing back music at the correct speed on both NTSC and PAL computers. Previous tracker software used playback routines which were synchronized to the refresh rate of the screen, which would cause incorrect playback on NTSC computers due to the higher refresh rate.