– First released in 2005. PowerShell – An object-oriented shell developed originally for Windows OS and now available to macOS and Linux. Qshell – A shell on the IBM i operating system based on POSIX and X/Open standards. rc – The default shell on Plan 9 from Bell Labs and Version 10 Unix written by Tom Duff. Ports have been made to various Unix-like operating systems. scsh – A Scheme Shell. wish – A windowing shell for Tcl/Tk. See also References System administration