How it’s made
In the competition, you are given a pack of samples (e.g. drum hits and single notes played on various instruments), and you have one hour to make a song out of them, usually in mod/s3m/xm/it format. My software of choice for producing this format is OpenMPT.
The majority of songs were made for #mod_shrine on espernet competitions, although there are some songs from competitions with mp3 (“all-gear”) format and a theme instead of a sample pack.