There is only one file type that uses the .OGZ extension:
Cube 2 Map File
An OGZ file is a map file used by games developed using the Cube 2 game engine. It contains a game map's geometry, spawn points, teleporters, item locations, and other settings. OGZ files can be used to store single-player or multiplayer maps.
OGZ files are stored in a compressed Gzip (GNU Zip) format. By convention, they are named map.ogz and stored in a unique map folder within the /packages/base directory of a Cube 2 game installation. They are saved with the files map.cfg, map.js, and optionally, entities.json.
OGZ files are similar to .MPZ and .BGZ files, which are used by different games based on the Cube 2 engine.
How do I create my own OGZ files?
You can use OGZ-Editor, a free, web-based tool, to write your own OGZ files. To learn more, visit OGZ-Editor's website.
You can open an OGZ file in Cube 2: Sauerbraten (cross-platform) using the /map command.
Updated: May 26, 2021