Since v2.04, bash has allowed you to intelligently program and extend its standard completion behavior to achieve complex command lines with just a few keystrokes. Imagine typing ssh [Tab] and being able to complete on hosts from your ~/.ssh/known_hosts files. Or typing man 3 str [Tab] and getting a list of all string handling functions in the UNIX manual. mount system: [Tab] would complete on all exported file-systems from the host called system, while make [Tab] would complete on all targets in Makefile. This project was conceived to produce programmable completion routines for the most common Linux/UNIX commands, reducing the amount of typing sysadmins and programmers need to do on a daily basis.
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).
PHP Shell is a shell wrapped in a PHP script. It's a tool you can use to execute arbiritary shell-commands or browse the filesystem on your remote Web server. This replaces, to a degree, a normal telnet-connection. You can use it for administration and maintenance of your Web site using commands like ps, free, du, df, and more.
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.
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.
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.
Wsh is a remote Unix and Windows NT shell that works via HTTP. The client script provides a shell-like prompt, encapsulating user commands into HTTP POST requests and sending them to the server script. The server script extracts and executes commands and returns STDOUT and STDERR output. Features include command line history support, file upload/download, and it can work through an HTTP proxy server.