This was initially created to test a 2d physics solver (box2d.js) in the context of an existing 404 error page from CargoMedia.
Based on "Google Gravity" by Mr. doob.
Try the Demo and check out the impact to the simulation when resizing or moving the browser window.
Make sure jekyll is installed
gem install jekyll
If operating on Windows, change code page for "cmd"
chcp 65001
Build the site and serve it on http://localhost:4000
jekyll serve --watch