Mozilla's WebRunner is a single-serving version of Firefox that strips away all the bells and whistles. There's no Web surfing to be done with this lightweight tool. Menus, extensions, themes, toolbars, and navigation have all been excised, like a sculptor cutting away excess marble.
What you're left with is a Site Specific Browser for Windows, Mac, or Linux that uses bookmark files with the WEBAPP extension. The installer configures these files to open in WebRunner, but there's no "launch program" icon or option. You just double-click on a WEBAPP file you've downloaded or created, and off you go, ready to get to work without getting distracted by the temptation to surf anywhere else.