This chapter is arranged by topical area to provide a quick reference to each of the Gas-phase Kinetics Library Subroutines. In addition to the subroutine call list itself, the purpose of the subroutine is briefly described. Where appropriate, the description refers to an equation number in Chemkin Theory Manual . Detailed descriptions of the subroutines are included alphabetically in Alphabetical Listing of the Gas-phase Kinetics Subroutine Library .