JavaScript

I have to admit, it wasn't love at first sight (I mean, just look at those tusks), but I'm now head over heels for Grunt.  Grunt is a task runner that chugs along in the background and, with the right set of plugins, can be set to automatically combine and minify CSS and JavaScript files; check HTML, Javascript, and JQuery for errors; compile Sass to CSS; write browser-compatible code; and more.