The developer console is a tool that allows you to run scripts in-game for testing and debugging scenarios. It is disabled by default but can be enabled from the Game Configuration. When enabled, you can press the tilde key (~) to bring up the console while playing your game. To use the console, simply enter a script into the text box and press enter to trigger it. See Scripting Reference for more information about the functions that are currently available.
This feature is a useful way to test the effect of certain functions/parameters before creating a script (for example, the timing/appearance of a light color change) or to troubleshoot an issue by displaying the value of a property at a specific point in time as shown in the example image below.