What is the Workspace Extender anyway?

I hear a lot of questions in the field about RES Subscriber and the Workspace Extender and whether they both sould be installed. There is a lot of confusion about it.
While it's actually quite simple. In the old days you had the Subscriber and the Subscriber Agent. Both products were able to integrate the applications running on the local computer into a remote session (let's call hat the Agent functionality). Subscriber can also be set as the user shell and is able to show a menu and some other features. The configuration can be done by running subscriber.exe with the /config switch or by editing the subscriber.ini. The Subscriber Agent can't be configured and only shows an icon in the system tray.
The RES PowerFuse Workspace Extender is just the new name for the new version of the Subscriber Agent that's all there is to it. And since the functionality of the Extender is also available in RES Subscriber there is no need to install both applications at the same time.

I hope this clears things up a bit.