defunkt/jquery-pjax

jquery-pjax is a jQuery plugin (jQuery is a JavaScript library that simplifies working with web pages) that makes navigating between pages on a website feel much faster. It does this by combining two browser technologies: ajax (a way to load new content from the server without refreshing the entire page) and pushState (a browser feature that lets you update the URL in the address bar without a full page reload). The name "pjax" is a portmanteau of these two techniques. When a user clicks a link on a pjax-enabled site, instead of the browser fetching and rendering a completely new page, pjax sends a behind-the-scenes request to the server, receives only the relevant portion of HTML, swaps out just the content area on the page, and updates the URL. The browser's Back and Forward buttons continue to work correctly because the URL history is properly maintained. This is faster because JavaScript and CSS files don't need to be re-downloaded and re-run on every navigation. For the best performance, the server should detect pjax requests (via a special HTTP header called X-PJAX) and respond with only the partial page content rather than the full page layout. The plugin exposes a detailed event system, events like pjax:beforeSend, pjax:success, pjax:timeout, and pjax:error, so you can hook into any stage of the navigation lifecycle for custom behavior. You would use this plugin on multi-page websites where you want a snappier, app-like navigation feel without rewriting your site as a single-page application. Note that the project is described as largely unmaintained with its feature set frozen. It is written in JavaScript and requires jQuery 1.8 or higher.