Gulp.js, an alternative to Grunt.js
I like Grunt.js. Since I started using it I have applied it to all my web projects. It has improved my workflow by providing a uniform way to perform operations such as combination of files, minification, optimization and testing, to name a few. And I already posted about it when I talked about how to make Javascript more testable.
Grunt made it a non-brainer thing to carry out tasks that were more cumbersome to setup before. More often than not I would not dare to clone a repo and give it a try, if I had to set up many dependencies. Now I feel relieved when I see it contains a Gruntfile.js file.