These use OTOY's X.IO streaming platform: the apps are rendered remotely on OTOY's servers, and streamed in real time on your machine. There are a few differences with embedded apps :
• streamed apps are rendered in a separate browser window instead of windows inside the WebDesktop
• streamed apps will run as fast as the servers will allow, even if you access them from a low-end machine
• accessing your WebDesktop drive, to open and save files, works through a favorite or drive D or P depending the app.
As such, unlike with embedded apps, to access your files you must first navigate to "WebDesktop" Favorite then /system/users/YOURLOGIN/