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 is a static site generator. What makes Janos different is that it is comes with free hosting, using Github Pages, and browser based content management. The only thing you need is a free account at Github and you are up and running in less than 5 minutes.