Ask HN: Other Uses for GitHub?

Apart from committing code, what other uses does GitHub serve?

I’ve seen a few other uses which are common:

- Filing issues. Found a bug? Great now submit an issue and hopefully it gets fixed soon.

- Jekyll blogs. GitHub is great for statically hosted blogs via their GitHub pages with Jekyll integration.

- Documentation. GitHub has a wiki feature that allows you to write docs for your project.

- Hosting static sites with GitHub Pages.

Apart from these what other applications does GitHub have?