Starting the UI tools
Factor handbook > UI developer tools

Next:UI tool keyboard shortcuts

The UI tools start automatically where possible:
On Windows, the tools start when the Factor executable is run.
On X11, the tools start if the DISPLAY environment variable is set.
On Mac OS X, the tools start if the application bundle is run.

In all cases, passing the -run=listener command line switch starts the terminal listener instead. The UI can be started from the terminal by issuing the following command:
USE: threads [ "" run ] in-thread