Webhooks have arrived

The concept of a WebHook is simple. A WebHook is an HTTP callback: an HTTP request that occurs when something happens; a simple event-notification via HTTP. A web application implementing WebHooks will make a request to a URL when certain things happen. When a web application enables users to register their own URLs, the users can then extend, customize, and integrate that application with their own custom extensions or even with other applications around the web.