Glossary of terms and definitions that can be loaded into Babylon, a dictionary viewing program; can be translated on-the-fly into several different languages by the Babylon program.

A BGL file is a scenery file used by Microsoft Flight Simulator. It contain scenery data, such as signs, towers, runways, helipads, and other objects. Each flying location in Microsoft Flight Simulator is created from one or more BGL files.

Several BGL files are included with Microsoft Flight simulator. While these files should not be edited, custom BGL files can be created to add extra airports and flying locations to the game.