[1] He was most notable for inventing the chemical line notations for structures (SMILES),[2][3][4] substructures (SMARTS) and reactions (SMIRKS).

[1] He also founded Daylight Chemical Information Systems, Inc.[5] Weininger studied at University of Rochester, first at the Eastman School of Music, then switched to chemistry.

Upon graduation, he was hired by the EPA directly in its National Water Quality Laboratory in Duluth, Minnesota to develop similar models for other chemicals.

Weininger realized the difficulty to balance the IUPAC nomenclature for chemicals, used by human, and the Wiswesser line notation which was more efficient for computer processing.

Weininger developed Simplified molecular-input line-entry system, or SMILES, such that it's easy for both humans and computers to understand.