All WHATWG standards are hosted on GitHub. A lot of the discussion takes place there too.
To run the standard's Makefile (i.e. to run "make" in your terminal) you need to have whatwg/xref in the same parent directory as the repository of your standard (e.g. whatwg/dom). In addition you need to have installed Anolis (ms2ger/anolis).
As the new Google Code it too might disappear. Fortunately the standards themselves will survive if this happens.