Clam Shell is a simple shell, designed to be a testbed for user interface ideas. It is a modular shell where the modules can be loaded or unloaded at runtime to expand or contract the functionality of the shell. This lets each user have a set of tools that they like to use, rather than one monolithic shell.
CURSEL is a freeware FMLI (Forms and Menu Language Interpreter) implementation for Linux and UNIX. CURSEL interprets Menu description files, which are simple text files, describing a character GUI (Menus, forms, text files) for character terminals (xterm, vt100, etc.). Pipes, shell escapes, backquoted expressions, and file redirection are supported, and when compiled with ncurses 5, CURSEL supports color.
GNU Bash is an sh-compatible command language interpreter that executes commands read from the standard input or from a file. Bash also incorporates useful features from the Korn and C shells (ksh and csh). Bash is intended to be a conforming implementation of the IEEE POSIX Shell and Tools specification (IEEE Working Group 1003.2).
GNU shtool is a compilation of small but very stable and portable shell scripts into a single shell tool. All ingredients were in successful use over many years in various free software projects. The compiled shtool program is intended to be used inside the source tree of free software packages. There it can overtake various (usually non-portable) tasks related to the building and installation of an free software package.
new_script is a program that creates shell script templates. It was developed to facilitate rapid creation of well-formed shell scripts containing the features expected in a production quality script, including traps for signal handling, command line option and argument processing, help messages invoked with the "-h" or "--help" options, and a framework for internal documentation.
Tcsh is an enhanced but completely compatible version of the Berkeley UNIX C shell. It is a command language interpreter usable both as an interactive login shell and a shell script command processor. It includes a command line editor, programmable word completion, command and file name completion, listing, spelling correction, a history mechanism, job control, and a bunch of small additions to the csh shell itself.