You can run several applications concurrently in OpenROAD Workbench. After you start the first application, select another application and click Run, Run. You can run any number of different applications, but no more than one instance of the same application at the same time.

Clicking the Stop toolbar button (or clicking Run, Stop) stops only the current application. If you want to stop another application, make it the current application and then click the Stop toolbar button.