XTree

XTree is a file manager program originally designed for use under DOS. It was published by Executive Systems, Inc. (ESI) and first released on 1 April 1985, and became highly popular. The program uses a character-mode interface, which has many elements typically associated with a graphical user interface. The program filled an acquired niche in the market, as DOS relied on command-line file management, until the generally unsuccessful DOS Shell shipped with MS-DOS 4.0. Even then, the speed and features of XTreeGold were superior — specifically support for the Zip compression format and ability to undelete files. The program also has the benefit of requiring very little memory, essential at a time when less than 640 kB of memory was available for programs to run.