Building an app on Facebook gives you the opportunity to deeply integrate into the core Facebook experience. Your app can integrate with many aspects of Facebook.com, including the News Feed and Notifications. All of the core Facebook Platform technologies, such as Social Plugins, the Graph API and Platform Dialogs are available to Apps on Facebook.com.

Apps on Facebook.com are web apps that are loaded in the context of Facebook. You can build your app using any language or tool chain that supports web programming, such as PHP, Python, Java or C#.

Apps on Facebook.com are loaded into a Canvas Page. A Canvas Page is quite literally a blank canvas within Facebook on which to run your app. You populate the Canvas Page by providing a Canvas URL that contains the HTML, JavaScript and CSS that make up your app. When a user requests the Canvas Page, we load the Canvas URL within an iframe on that page. This results in your app being displayed within the standard Facebook chrome.