Spawn is better than Exec? Sometimes!
Using exec in an Action is flexible, because you could use nearly any command the OS understands. But it is always synchronous waiting for a response within the Actions.
But sometimes it is feasible - or even required - to have the program stay open and running while several Actions are executed.
We added spawn for this. With spawn any command the OS understands could be started (like it is with exec), but the response of spawn is a handle to the resulting child process. The current Action as well as all upcoming Actions taking place for that Trigger could use that handle to communicate with that program.