Autojump is a tool that acts as a complement to cd: it makes navigating your filesystem a lot faster. It works by automagically maintaining a database of the directories you use the most from the command line, and allows you to jump back and forth between them, by typing just a few letters of the name of the directory you want to jump to. It works for Linux, Mac, and Cygwin under Windows.
Shell Script Loader is a framework (in a helper script) that can be used by shell-script-based applications for easy including or loading of co-shell-scripts or subscripts. With this utility, scripters may now be able to apply multi-file or module-oriented scripting or programming in shells just like the way they are always done in known languages like Perl, PHP, and Ruby. The provided functions are load(), include(), and call() with the extended versions loadx(), includex(), and callx(). The extended versions can accept glob patterns and regular expressions. Shell Script Loader supports many shells including the very old ones like bash, zsh, ksh, pdksh, sh, ash, dsh, and all shells based on the original sh. Scripts made with Shell Script Loader may also be compiled to form a single script. A generic compiler written in awk is already available.