4DOS

4DOS is a command line interpreter by JP Software, designed to replace the default command interpreter COMMAND.COM in DOS and Windows 95/98/Me. The 4DOS family of programs are meant to replace the default command processor. 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.

A graphical version of 4DOS, 4OS2 and 4NT, called Take Command was released with a feature set corresponding to version 4DOS 5.5, and 4OS2, 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.

4OS2 is a similar replacement for IBM's OS/2 command interpreter. This was first released at the same time as 4DOS version 4, and has a similar feature set. Like 4DOS, this is released as open source, and is still being actively developed. It appears in the feature set of 2011's eComStation 2.10, and in the freeware os2free project. Take Command for OS/2 is not currently being developed.

4NT was first released as 4DOS for Windows NT (versions 1.x, 2.x), but became 4NT until the restructure after version 8. The program is a recompile of 4OS2, and continues to have features of OS/2's command processor (CMD.EXE), such as running REXX scripts, and EXTPROC support. A corresponding Take Command/32 exists for this, version 1 corresponding to 4NT 2.5. 4NT and Take Command/32 were released in both ANSI (Windows 9x) and Unicode (Windows NT) forms, with the ANSI version dropped at version 5.

A new Win32 program Tabbed Command Interface, was released at the time of 4NT version 7. This program allowed one to attach (thereby reducing screen clutter) and unattach tabbed consoles to a single Window. This program requires Windows XP or later.

A new version of Take Command extends the original Tabbed Command Interface, expanded with extra windows to allow input to be composed, to graphically navigate directories and files, and extra features. 4NT is bundled as Take Command Console. A light or feature-reduced version of TCC is released as a free download. JP Software then released TC (full pack of TCI + TCC), or TCLE (TCI + TCC/LE), or TCC (just the command utility), or TCC/LE. This has been released from versions 9 to 12.1, corresponding to the underlying 4NT/TCC version.