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).
fish, the friendly interactive shell is a shell that is focused on interactive use, discoverability, and user friendliness. The design goal of fish is to give the user a rich set of powerful features in a way that is easy to discover, remember, and use. fish features a user-friendly and powerful tab-completion, including descriptions of every completion, tab-completion of strings with wildcards, and many completions for specific commands. It also features an extensive and discoverable help system. A special help command gives access to all the fish documentation in your preferred Web browser. Other features include syntax highlighting with extensive error checking, support for the X clipboard, smart terminal handling based on terminfo, an easy to search, no duplicates history.
Zenity is a tool that allows you to display Gtk+ dialog boxes from the command line and through shell scripts. It is similar to gdialog, but is intended to be saner. It comes from the same family as dialog, Xdialog, and cdialog, but it surpasses those projects by having a cooler name.
fli4l is a single-floppy Linux-based ISDN/DSL/ethernet-router. It features configuration with some simple ASCII-files, several possible connection-flavors (in/out/callback, and raw IP/PPP), channel bundling (an extra channel can be added through a Windows/Unix-client), configuration of multiple networks, least-cost routing, automatic choice of provider, display/calculation of connection times and costs, and a Windows/Unix client to control dial/hangup, monitor traffic and monitor incoming calls on ISDN (see screenshot).
execline is a very light, non-interactive scripting language, which is similar to a shell. Simple shell scripts can be easily rewritten in the execline language, improving performance and memory usage. execline was designed for use in embedded systems, but works on most Unix flavors.