.CELX File Extension

Script used by Celestia, a free universe browsing application; written using the Lua scripting language and specifies instructions for the location and observation angle in the universe over time; used for marking locations in space as well as for creating tours of the universe.

CELX files can be run in Celestia by selecting File → Run Script.. from the application menu and then selecting your script.

NOTE: CELX files are created in a plain text format and are written using a text editor.