In a Chromium Blog post yesterday, a new contextual menu API was introduced, as well as two experimental ones: and Infobar and Omnibox API to offer developer more options when creating both extensions and webapps. Another possible API coming down the pipe would be sidebar functionality.
As Google’s Aleksey Shlyapnikov has proposed, a sidebar API would give “an extension control over a sidebar panel – a per-tab split-pane HTML container with the ability to resize horizontally to the right of the main page content.”
It makes sense, since webapps are going to need as much flexibility as they can get from Chrome’s existing windows. Sidewiki, which is a Google-made extension that allows users to add additional content to web pages, could use this type of API; currently Sidewiki pops out under the extension as opposed to being a full sidebar.
You can read more about the experimental sidebar API here. In the proposal, Shlyapnikove says that sidebar functionality can be already be tested for development purposes by using the “–enable-experimental-extension-apis” switch.