Unlike many programmers who use a single text editor for nearly all tasks, I tend to use a couple of different ones: vi (vim) or nedit for quick edits on UNIX/Linux systems, notepad++ for quick edits on Windows systems, and TextEdit for quick edits on Mac boxes. However, if I know I will be working on something for an extended period, I often choose to use...

jEdit Programmer's Text Editor

jEdit is a Java-based application with a rich feature set and a larger body of communinty contributed add-on plugin modules. This multi-platform Open Source editor runs on everything I use: Microsoft Windows, Linux, and Mac OS X. This means that I don't have to adjust much in the way of muscle-memory-typing to get things done regardless of what platform I'm using at the time.