Janos is a static site generator with multiple templates to use. Janos fully operates in the browser. It uses Metalsmith with a bit of Webpack magic sprinkled on top, to make it all work inside a browser. It is tightly integrated with GitHub to automatically host your site, using GitHub pages. If you don't know what all that means, that's ok: You should be able to work with Janos without knowing all the ins and outs of those technologies.
Janos can be used by anybody. It is still far from a 1.0 release, but it is definitely usable. The site you are reading right now is (obviously) created using Janos.
You can start today by going to the admin of this site, and completing the wizard for creating your own website. The only thing you need is a GitHub account, which you can create for free.
The wizard will create a repository in your GitHub account, and turn on GitHub pages and that's it. Now you have a Janos website yourself with content management that only you can use by going to the GitHub pages url with /admin added behind. Anyone visiting your website can start their own website as well, by going to your /admin. They won't be able to edit your website. The only thing available for them is the wizard so that they can create a Janos website as well.
Janos is the only self-replicating entity for which a R0 above 1 is a good thing. Changed file.