GAR Architecture
The GAR system is a similar system to the BSD ports collection. It's a mechanism for automating the compilation and installation of third-party source code. It appears in the form of a tree of directories containing Makefiles and other ancillary bookkeeping files (such as installation manifests and checksum lists).
GAR is currently used by The LNX-BBC project, as well as the GARNOME distribution of GNOME.
Of interest to people wishing to learn the GAR system is this overview of the ports collection.