GAP package Sophus: Computing in nilpotent Lie algebras. Sophusis a GAP4 package to compute with nilpotent Lie algebras over finite prime fields. In particular, the package can be used to compute certain central extensions and the automorphism group of such Lie algebras.Sophusalso enables its user to test isomorphism between two nilpotent Lie algebras. The author of the package used it to construct all Lie algebras of dimension at most 9 over F4