The 001 file extension is the first file of a split archive created by various compression tools. The general file sequence is 001, 002, 003, etc.. All parts of the multi-volume archive are needed to extract the content.
The 001 file extension is used for Ghost backup images and created with Norton Ghost. Because of the Ghost image files limited to the 2GB file size limit in DOS. If a partition larger than 2GB, Ghost would split it into two or more smaller files. So other parts of the split have extensions “.002”,”.003” etc.
The 001 file extension is also used by various Fax programs.
The 001 file extension is used by Snes9x emulator of Super Nintendo Entertainment System. This file type contains saved player’s state in a game. The .001 file contains saved player's position in a game.
001 file extension also used by ICS text. ICS(Image Command Set) is a text file of commands to produce a distributable electronic document.
The 001 file extension is a backup of user’s project file which is used by Multimedia Fusion editor system. Multimedia Fusion software authoring tool mostly used for game development. The 001 is the first part of a backup file which contains backup of user's data created in the Multimedia Fusion.