4DOS

4DOS

Developer(s)	JP Software
Stable release	8.00 (Open Source in 2009) / 7.50.130 (JPSoft in 2004)
Operating system	MS-DOS, Windows
Type	Command shell
License	modified MIT License that does not qualify as open source by Open Source Initiative or Free Software Foundation standards
Website	4dos.info

4DOS is a command line interpreter by JP Software, designed to replace the default command interpreter COMMAND.COM in MS-DOS and Windows 95/98/SE/ME. 4OS2 and 4NT replace CMD.EXE in OS/2 and Windows NT respectively. 4DOS was written by Rex Conn and Tom Rawson; it was first released in 1989. These programs can also be initiated from the command line and/or called by scripts.

4DOS is most often used with the MS-DOS-Windows 95 stream of operating systems and it can be also used with Windows NT type machines, IBM PC DOS and also later DR DOS versions. Since Windows NT-2000 includes both COMMAND.COM and CMD.EXE, 4DOS and 4NT and derivatives can both be installed. Earlier versions of 4OS2 can be run under Windows NT, and OS/2 can run the two MS-DOS and Windows NT shells, all three can be used on Windows NT-type machines and OS/2 multiple boot machines.

Among the many commands, statements and functions in 4DOS and lacking in MS-DOS/Windows 95/98 COMMAND.COM are reading keyboard input and a simpler method of working with colors of screen and text.

The default file extension for 4DOS scripts is .btm.

A graphical version of 4DOS, 4OS2, and 4NT, called Take Command, was released with a feature set corresponding to version 4DOS 5.5, 4OS2, and 4NT 2.5 and updated after this. Development on this line stopped with the corresponding character-mode versions. There was a graphical program Take Command/16, for Windows 3.1.