The `trunk/debathena` subdirectory of the source tree contains Debian/Ubuntu-specific materials, also known
as "Debathena".  The contents are:

 * `debathena` - Debathena-specific software packages such as PAM and NSS modules.
 * `config` - Packages for configuring native system software in a manner appropriate for Athena.
 * `meta` - Packages which contain nothing but dependencies on other packages and serve as an installation convenience.
 * `scripts` - Build scripts and supporting materials.

Debian software used by Debathena:

  * `schroot` - Used to manage build chroot environments for each Debian/Ubuntu version.  We use the device schroot type with aufs union mounts, which allows rapid construction of ephemeral copies of template "source" chroots, so that every binary package build is done in a clean environment.  *N.B.* Also used by login chroots in debathena-cluster

  * `debuild` - Used to create Debian source packages from package
    source directories.

  * `sbuild` - Used to build binary packages from source packages inside
    schroot environments.

  * `equivs` - Used to create packages which only contain dependency
    information.  Somewhat of a dirty hack, since it doesn't keep
    proper changelogs, but it reduces overhead.  *N.B. Being phased out as of 2011/12*

  * CDBS (Common Debian Build System) - Referenced by debian/rules
    files in packages.  Contains standard build rules to cut down on
    per-package boilerplate.

  * `reprepro` - Used to upload packages into the apt repositories.

  * `approx` - Used to create a local cache of Debian packages on the
    build server.  This cache is referenced by the build chroots for
    improved performance.