Chrome has its canary channel and Firefox has its nightly builds. Now Internet Explorer is joining the frequent updater trend, with a new Developer Channel that will run separately to the mainstream IE release.
IE has traditionally been the slowest of the browsers to update, in part because its update cycle is tied to Windows releases. The Developer Channel release breaks that connection, and can be installed alongside the current mainstream IE11 release. It only runs on Windows 7 and Windows 8.1.
The frequency of the update cycle hasn't been fully specified, but it doesn't look as if we'll see nightly builds: the announcement post merely says "as we work on new features and standards, we will continue to share early code through the IE Developer Channel". The initial release includes enhanced F12 developer tools, the ability to use Xbox controllers and support for the WebDriver automated testing standard. Hit the link below to download it.