MacOS

Installing the GAP distribution with all the packages and full data libraries from source code requires a working C and C++ development environment on your system as well as GNU make.

You need to install the Apple developer tools. If you are on macOS 10.11 or newer, this can be achieved by opening a terminal window and entering the command

xcode-select --install

A window will appear asking you whether you would like to install the command line developer tools. Confirm this by clicking the “Install” button. After this completed, you can verify that it worked by verifying that the directory /Library/Developer/CommandLineTools/usr/bin/ exists and contains executables such as clang and clang++.

Note that to obtain a fully functional GAP installation you need not only to compile the core system, but also some of its packages. To install GAP using the source distribution, perform the following steps:

Verify that all required tools are installed (see above and also get gmp and readline). Use your package manager (e.g. brew, port or fink) for that.

Choose your preferred archive format and download the corresponding archive.

gap-4.13.1.tar.gz	515 MB	sha256: `9794dbdba6fb998e0a2d0aa8ce21fc8848ad3d3f9cc9993b0b8e20be7e1dbeba`
gap-4.13.1.zip	533 MB	sha256: `8298f4a8c78197d8509f01a1f841a09eaac4880dab273fae2ba82bc30eb69aa8`

Unpack the archive.
Compile the GAP core system by running
```
./configure && make
```
in the unpacked directory.
Change to the pkg subdirectory and call
```
../bin/BuildPackages.sh
```
to run the script which will build most of the packages that require compilation (provided sufficiently many libraries, headers and tools are available). If something doesn’t work on your system, please refer to the README file provided with the corresponding package.
Adjust some links/scripts/icons etc., to make the new version of GAP available to the users of your machine.
Optional: run a few tests.

Alternatives

Homebrew

Homebrew is a package manager for macOS. If you use Homebrew, you can install GAP using the GAP Homebrew tap.

Gap.app

Gap.app is a native macOS frontend and distribution of GAP, developed by Russ Woodroofe. The “Gap.app + GAP” edition includes a fairly complete copy of GAP, and can be installed by simply downloading a disk image and dragging Gap.app to the Applications folder. You can also install the built-in GAP for use from your usual terminal via the Install GAP Command For Shell menu option (found under the Gap menu in the GUI frontend).

The included GAP comes with working copies of most of the packages in the standard GAP distribution. Gap.app is compatible with XGAP, and allows interactive display of subgroup lattices with the GraphicSubgroupLattice command. The version of GAP that comes with Gap.app may lag slightly behind the very latest. Full details on the currently included GAP may be found in the Gap.app FAQ.