HTTP server, client, tests, and examples. All required repositories are included as submodules so if you clone with --recursive you should have everything you need for building.
When using Open Dylan 2011.1 or earlier, add http/registry to the OPEN_DYLAN_USER_REGISTRIES environment variable before building.
Building the documentation requires that Python be able to find the Dylan extensions to Sphinx.
The easiest way to do this is to check them out somewhere and put them on your PYTHONPATH: