4DOS

4DOS
Developer(s)JP Software
Stable release
8.00 (Source available in 2009) / 7.50.130 (JPSoft in 2004)
Operating systemMS-DOS, Windows
TypeCommand shell
Licensemodified MIT License that does not qualify as open source by Open Source Initiative or Free Software Foundation standards
Website4dos.info

4DOS is a command-line interpreter by JP Software, designed to replace the default command interpreter COMMAND.COM in MS-DOS and Windows. It was written by Rex C. Conn and Tom Rawson and first released in 1989. Compared to the default, it has a large number of enhancements.

4OS2 and 4NT are similar products that replace cmd.exe in OS/2 and Windows NT respectively.