Emacs. This comes first into my mind when I hear the word "programming tool".<p>Emacs' default configuration is horrible. It took me many months to get used to it and to realize a perfectly convenient configuration. But since I did that 25 years ago I have stuck with it to this day. Emacs' killer feature is its almost unlimited programmability. org-mode is just one awesome example. There are several other good editors (vim, sublime, atom etc.) but none of them comes close to the power of Emacs.
I can't hear about regular expressions without wanting to tell anybody that loves it so much to try Haskell. Really.<p>Monadic parsers are so much better, regular expressions become pointless. I've written an entire email server, with literally thousands of lines of parsers, and the only place I've used regular expressions is for accepting them from the user, in a configuration file.
I’m sad that the author seemed to know neither the original proper wording, source, nor context of the jwz quote about regular expressions. Maybe JWZ’s quote has just spread too far or too wide. Either way, I think Jeff Atwood hit this nail on its head: <a href="http://blog.codinghorror.com/regular-expressions-now-you-have-two-problems/" rel="nofollow">http://blog.codinghorror.com/regular-expressions-now-you-hav...</a> .