pjax: Load HTML from server into current page without a full page load, written in Ruby

http://pjax.heroku.com/

From the pjax website:

pjax loads html from your server into the current page without a full page load. It’s ajax with real permalinks, page titles, and a working back button that fully degrades.

The idea is you can’t tell the difference between pjax page loads and normal page loads. On complicated sites, browsing just “feels faster.”

Github Repo