A2B file is an instrument library file used by audio editing software Adlib Tracker II. Adblib Tracker II supports up to 18 audio channels. The tool requires an audio card equipped with OLP3 chip featured in older Creative Labs devices.

Adlib Tracker II offers 255 various instruments stored in A2B database. The program is still actively developed and its latest version released in 2018. Adlib Tracker II debuted in 2000.