Single page application

A Single Page Application (SPA) is a self-contained Web Application. In a SPA, all necessary code - HTML, Javascript, and CSS resides in a single HTML file. The term was coined by Steve Yen in 2005.

One important property of SPAs is that they can be executed from a local file using the File URI scheme, unlike normal web pages which must be served over HTTP. This gives users the ability to download the SPA from a server and run the file from a local storage device, without having to run any server software.

In order to store and update data, SPAs must be self-modifying. That is, the SPA must be capable of writing itself to disk, including a representation of the state that is to be persisted.

Currently, TiddlyWiki is the best known example of an SPA.