Using Unix as an IDE (2012)
Maybe this is implicitly assumed, but a terminal multiplexer such as tmux is also a useful utility for using unix as an IDE. For example, you can have a pane for your code in an editor like vim, and a pane for running your tests next to it, and maybe another pane for an interactive shell of your language. Lacking a consistent local development environment, tmux is indispensable when I ssh into into my remote development environment.