1. A computer-implemented method, comprising: an activity generator representing with an output device one or more available command units that can be executed through a command shell application, the one or more command units being executable through the command shell application by the command shell application allowing a command corresponding to each of the one or more command units to be entered by user input into the command shell application and by the command shell application responding to the user-entered command by invoking the command unit corresponding to the user-entered command; the activity generator receiving user input from an input device, the user input selecting one or more selected command units of the available command units; and in response to the user input: the activity generator automatically generating source code from the one or more selected command units, generating the source code comprising mapping properties of the one or more selected command units onto workflow activity properties, the mapping comprising using a code object model to map properties of the one or more selected command units onto workflow activity properties; and automatically compiling the source code to generate one or more workflow activities, each of which is configured to be executed by a workflow engine, the workflow engine, the command shell application, and the activity generator being different from each other.