MOL2 is an extension characteristic of specialized programs for molecular modeling. MOL2 is a file used to store a model of a molecule. The data in such a file is saved in SYBYL format. Technically, MOL2 is a plain text file containing all the information necessary to visualize the molecule (including 3D coordinates).

Very often MOL2 files are associated with the SYBYL-X program produced by Tripos.