Jekyll is used by default for GitHub Pages sites, so I'm sure companies like GitHub would appreciate the savings from speedups like this.
I believe GitHub Wikis are also rendered with Jekyll? Without customization capabilities on the user side, Gojekyll could be used here, too.
I don’t think you can actually load custom plugins, at least that wasn't the case the last time I looked.
> I believe GitHub Wikis are also rendered with Jekyll?
I don't see a reason to, they're just flat markdown documents, not a blog.