unix/      - Architectural files for testing on unix-like systems
             (assuming gcc and pthreads).
           - Maintained by Kieran Mansley <kieran@recoil.org>

msvc6/     - Architectural files for Microsoft Visual C++ 6.0.
           - Maintained by Simon Goldschmidt <sgoldschmidt@de.pepperl-fuchs.com>

old/       - Ports that are no longer actively maintained