.. _about_software: About the Software =================== There are two programs installed by the instructions in :ref:`download_and_install`. The underlying software library is called ``Fokko`` in honor of its primary architect Fokko du Cloux. Fokko worked on the software in 2004 and 2005. Since then Marc van Leeuwen is the primary software developer. The program ``atlas`` is designed for interactive exploration of real reductive Lie groups and their representations. It has been developed by Marc van Leeuwen since 2006. It is built on a programming language ``axis``, also developed by Marc van Leeuwen. The atlas software invokes (invisibly to the user!) the libraries of ``Fokko`` to create mathematical objects; then the ``axis`` language offers standard programming tools (loops, variables, scripts, and so on) with which the user can manipulate them. An important part of ``atlas`` is the (constantly growing) library of predefined scripts, which can be used or modified to do interesting mathematical tasks. These files are found in the ``atlas-scripts`` directory, and have the suffix ``.at`` (or occasionally ``.ax``). This library has been developed by Marc van Leeuwen, Jeffrey Adams, Annegret Paul, David Vogan and others.