Ad Lib, Inc. was a Canadian manufacturer of sound cards and other computer equipment founded by Martin Prevel, a former professor of music and vice-dean of the music department at the Université Laval. The company's best known product, the AdLib Music Synthesizer Card (ALMSC), or simply the AdLib as it was called, was the first add-on sound card for IBM compatibles to achieve widespread acceptance, becoming the first de facto standard for audio reproduction.

A sound card is an internal expansion card that provides input and output of audio signals to and from a computer under the control of computer programs. The term sound card is also applied to external audio interfaces used for professional audio applications.