Don't forget the text editor
Text editors are important for many tasks, from editing configuration files, nudging cron jobs, and manipulating XML files to quickly pushing out a README. Luckily, there are a number of interesting editors available. Here's a brief introduction to nine intriguing choices. While some may be better suited to certain tasks, it's no one tool is better than another for all tasks. Try them all and use the ones you like best.
Old favorite vi (or one of its variants, such as Vim or Elvis) is available on most *nix systems. If you are a system administrator moving from one *nix system to another, the one reliable fact is that vi will work, macros and all. Once you have learned the keystrokes, swapping words at the boundaries, replacing sections of text, or transversing through a large file with vi is efficient, fast, and predictable. However, its initial learning curve is somewhat steep, and there is no real GUI.
Gedit and Kate
Also: Intro to HTML editors