what are your useful tools for a programmers?

Hey /prog/,

what are your useful tools for a programmers?
I can think og:
>sublime or emacs with some configuration
>git
>...

windows calculator for number conversions, google for teaching yourself things you should know but dont because you're a fucking idiot.  Depending on what you're doing - burp suite, specialty tools that you made, coworkers have made, IRC for group communication, cloud storage for collaboration.  I really suggest looking into zoho's business options, lots of good stuff there.  Probably more, im sure you'll get plenty of ``Enterprise Quality'' suggestions from this board.