Canvas+ has some special API that are exclusive of this webview engine and that are not available in the other engines.
Some of this features can also be accomplished with Cordova or a Cordova plugin and are just legacy.
Different methods to have acceso to the device information.
Methods to access the dialog/prompt API.
Accelerometer and gyroscope API.
Methods to poxify different functions of the WebView environment, like Audio objects and XHR.
The “Cocoon.Touch” object holds some functions to handle the touch events in both surfaces ( Cocoon & WebView )
Varios utilities like texture reduction or screen capturing.
Canvas+ internal webview API.