TorqueScript is a custom scripting language used by the Torque family of engines. It has a C-like syntax, but is dynamically typed. It is mostly intended to be used to script gameplay logic callbacks, rather than performing complex AI or user interaction routines. In a way it acts as the 'glue' that attaches different pieces of the engine together to make your game.
It is also heavily relied upon to serialise objects to disk, such as levels, GUIs, datablocks, and other game data. Here's an example of a simple TorqueScript file:
If you want to edit TorqueScript, have a look at our editor and IDE list. To learn about TorqueScript's syntax, take a look at the official syntax guide, or browse the pages in this category:
MakingIndieGames has made a great introductory video on TorqueScript.