One or more available command units can be represented with a computer output device. The available command units can be command units from one or more snapins, such as one or more snapins that include command units to be run with a shell application. User input can be received from an input device, the user input selecting one or more selected command units of the available command units. In response to the user input, source code can be automatically generated from the one or more command units, and the source code can be automatically compiled to generate one or more workflow activities.