by Microsoft) IBM OS/2 (and derivatives such as eComStation and ArcaOS) has the cmd.exe processor. This copies the COMMAND.COM commands, with extensions to REXX. cmd.exe is part of the Windows NT stream of operating systems. Yet another cmd.exe is a stripped-down shell for Windows CE 3.0. An MS-DOS type interpreter called PocketDOS has been ported to Windows CE machines; the most recent release is almost identical to MS-DOS 6.22 and can also run Windows 1, 2, and 3.0, QBasic and other development tools, 4NT and 4DOS. The latest release includes several shells, namely MS-DOS 6.22, PC DOS 7, DR DOS 3.xx, and others. Windows users might use the CScript interface to alternate programs, from command-line. PowerShell provides a command-line interface, but its applets are not written in Shell script. Implementations of the Unix shell are also available as part of the POSIX sub-system, Cygwin, MKS Toolkit, UWIN, Hamilton C shell and other software packages. Available shells for these interoperability tools include csh, ksh, sh, Bash, rsh, tclsh and less commonly zsh, psh Implementations of PHP have a shell for interactive use called php-cli. Standard Tcl/Tk has two interactive shells, Tclsh and Wish, the latter being the GUI version. Python, Ruby, Lua, XLNT, and other interpreters also have command shells for interactive use. FreeBSD uses tcsh as its default interactive shell for the superuser, and ash as default scripting shell. Many Linux distributions have the Bash implementation of the Unix shell. Apple macOS and some Linux distributions use zsh. Previously, macOS used tcsh and Bash. Embedded Linux (and other embedded Unix-like) devices often use the Ash implementation of the Unix shell, as part of Busybox. Android uses the mksh shell, which replaces a shell derived from ash that was used in older Android versions, supplemented with commands from the separate toolbox binary. Routers with Cisco IOS, Junos and many others are commonly configured from the command line. The Plan 9 operating system uses the rc shell which is similar in design to the Bourne shell. Scripting Most command-line interpreters support scripting, to various extents. (They are, after all, interpreters of an interpreted programming language, albeit in many cases the language is unique to the particular command-line interpreter.) They will interpret scripts (variously termed shell scripts or batch files) written in the language that they interpret. Some command-line interpreters also incorporate the interpreter engines of other languages, such as REXX, in addition