4DOS

4DOS
Developer(s)JP Software
Stable release
8.00 (Open Source in 2009) / 7.50.130 (JPSoft in 2004)
Operating systemDOS, 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 Microsoft 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.