You can further customize your GitHub Pages site in many ways.

Creating a custom 404 page for your GitHub Pages site

You can display a custom 404 error page when people try to access nonexistent pages on your site.

MIME types on GitHub Pages

GitHub Pages supports more than 750 MIME types across 1,000s of file extensions. The list of supported MIME types is generated from the mime-db project, which aggregates MIME types from the Apache and Nginx projects as well as the official IANA list of internet content types.

Should I rename <username.github.com> repositories to <username.github.io>?

You do not need to rename old repositories from the .com name to the .io name, as GitHub Pages will continue to route the old repositories. However, we highly recommend that new repositories take the username.github.io format.

Using a static site generator other than Jekyll

You can use a static site generator other than Jekyll for your GitHub Pages site by using a different build process.

Using submodules with Pages

You can use submodules with GitHub Pages with a few conditions.