GitHub Pages now runs Jekyll 2.2.0

To be specific, all sites are processed through Jekyll, unless you add a `.nojekyll` file. Non-Jekyll files (like HTML or CSS) are passed transparently through Jekyll untouched. Adding the dashes to the file header simply tells Jekyll to work its magic.

I believe the files are generated on Github's servers. You can install Jekyll locally to get the same workflow locally.

When you run Jekyll, it spits out an `_site` folder - which is the generated HTML/CSS/JS of your site. Locally, when you run the Jekyll server it generates the site and then serves from that folder for you to preview.

With GitHub pages, you push a repository containing the Markdown files, but not the full generated site. On GitHub's server it generates the site and then serves it. You will want to add the `_site` folder to your `.gitignore`.

I was planning to write a guide on this... you know, some day...

From what I understand, Jekyll (the web site builder) automatically runs on their end. And, as the other poster mentioned, you can simulate the result of this by running a local copy of Jekyll on your local checkout.

But in the end, only the Jekyll input configuration/source data is required. The rest is optional.

Pages are generated on Github servers. As somebody mentioned you can run Jekyll locally to preview the rendered pages or simply push to github and review online.

It looks like you just commit plaintext files (or markdown, or any of several other formats) into your repo and they get built into HTML by jekyll and hosted as articles on your site.

http://jekyllrb.com/docs/structure/

As an aside, if your Jekyll workflow requires custom plugins (which Github doesn't support), you can always generate the site locally and push the contents of the _site folder to Github.

As said, they are generated on Github. There are online content editors like http://prose.io and http://tinypress.co (for Github page blogging) though.