A lightweight JS framework for fast navigation and page updates from YouTube Using progressive enhancement and HTML5, SPF integrates with your site to enable a faster, more fluid user experience by updating just the sections of the page that change during navigation, not the whole page. SPF provides a response format for sending document fragments, a robust system for script and style management,
![SPF](https://cdn-ak-scissors.b.st-hatena.com/image/square/a17ae76c1979091daf748b836b0ee3fbd7b36852/height=288;version=1;width=512/http%3A%2F%2Fyoutube.github.io%2Fspfjs%2Fassets%2Fimages%2Fanimation-static-340x178.gif)