Run Script...

Runs a selected Lua script. Disabled if a script is already running. A number of sample scripts are provided in the Scripts folder.

Run Clipboard

Runs Lua code stored in the clipboard. Disabled if a script is running.

Run Recent

This submenu lets you run a recently executed script. The most recent script is always the first item (a quick way to run the first script is to hit the "1" key). The maximum number of scripts remembered is determined by a setting (initially 20) which you can change in Preferences > File. The submenu is disabled if a script is running.

Stop Script

Abort the currently running script.

Save Canvas...

Brings up the standard file saving dialog so you can save the current canvas in a PNG file. Disabled if there is no canvas. Note that you can save a canvas created by a running script at any time.

Delete Canvas

This item is disabled if there is no canvas or a script is running. Some scripts (like icons.lua) don't delete the canvas when they finish, so use this item to delete the canvas and return to the startup.lua interface. Other ways to delete the canvas: click anywhere in the viewport or hit the escape key.

Preferences...

Opens the Preferences dialog so you can change various settings. [On a Mac this item is in the application menu.]