iCan is an intelligent, community-driven command line that helps you to automate any kind of task arising in your daily Linux use. It is extensible through simple Lua modules, which run in a sandbox environment. It is designed to learn what you do and make things easier for you, every time you do something.
timeplotters is a collection of command line tools for visualizing temporal data. It is especially useful for visualizing data from ad-hoc program logs, helping you to spot patterns and anomalies that you would not otherwise see by just watching how the program works or by looking at the logs with the naked eye. Its input format is tailored to event types typically seen in program logs, and the visualization methods are tailored to the questions typically asked about program performance (e.g. distribution of activity durations).
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.