GWE comes with a java API that allows to create component interfaces or applications (GWE client application) which interact with the GWE daemon controlling the described clusters. These daemons can be deployed and installed by any client on-demand or automatically (if the client detects there is no daemon running remotely, and it launches it if it is installed but not running). Using this API the generic GWE client applications have been created as well as specialized ones (as detailed in the documents of the GWE Powered Tools section).
GWE client applications communicate with remote daemons through a secure SSH tunnel (transparently established), so all communication will be secured and without requiring any cluster administration tasks such as opening specific ports, or installing any software, in fact not even SSH-ing into the clusters is necessary: GWE will take care of everything from here!