Several "official" GAP packages are included, all of which are available from http://www.gap-system.org/Packages/packages.html. They are all released under the GPL with the following exception: GRAPE contains nauty (written by Brendon McKay).

A brief description of each package follows:

braid is a GAP package for computing with braids, covering curves, and Hurwitz spaces.

CTblLib - The GAP Character Table Library

DESIGN is a package for classifying, partitioning and studying block designs.

FactInt is a package providing routines for factoring integers, in particular:

- Pollard's p-1
- Williams' p+1
- Elliptic Curves Method (ECM)
- Continued Fraction Algorithm (CFRAC)
- Multiple Polynomial Quadratic Sieve (MPQS)

GAPDoc is a package containing a definition of a structure for GAP documentation, based on XML. It also contains conversion programs for producing text-, DVI-, PDF- or HTML-versions of such documents, with hyperlinks if possible.

GRAPE ("GRaph Algorithms using PErmutation groups") is a package for computing with graphs and groups, and is primarily designed for constructing and analysing graphs related to groups, finite geometries, and designs.

HAP ("Homological Algebra Programming") is a GAP package providing some functions for group cohomology computation.

LAGUNA ("Lie AlGebras and UNits of group Algebras") package provides functionality for calculation of the normalized unit group of the modular group algebra of the finite p-group and for investigation of Lie algebra associated with group algebras and other associative algebras.

SONATA ("System Of Nearrings And Their Applications") is a package which constructs finite nearrings and related objects.

TORIC is a GAP package for computing with toric varieties.