all of it is baked by Awestruct - static page generation tool written by Red Hat folks and the community. If you know Ruby it shouldn't be that hard to get into it. For arquillian.org (which we host on GitHub btw) we mainly use textile, however we would love to convert it to asciidoc sooner than later.
Lately I've provided Docker container for the whole tool chain so if you are interested in more details how it all works together, give it a spin! I hope it does not only work on my machine
We have quite a bit of things to improve there as well so if you would be interested in contributing you have all my help!