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.
lib_MTA is a BASH function library for dealing with email. It provides support for unencrypted and TLS-encrypted relaying of email with attachments, special mailing list filtering, and From address spoofing. The installation automatically sets up a mailing list filtering infrastructure that can be enabled with a few simple steps. Example scripts for relaying email and filtering mailing lists are included in the package with the library. Desktop users can employee a simple script to send email to remote addresses without the need for a local MTA, provided they have relay access via Gmail or their ISP.