Atlas of Lie Groups and
Quick Start:Download a gzipped tar (tgz) file from the downloads section of the Atlas Project Page at google. The latest stable unix version (including Mac) is atlas_0.5.1.tgz.
Unpack the file; if this doesn't happen automatically type:
tar xvfz atlas_0.5.1.tgz
to create the atlas_0.5.1 directory.
Proceed to installing the atlas software.
To download the latest (development) version of the software go to downloading the atlas software using git.