The document discusses using Grunt, a task runner, for WordPress development. Grunt allows automating tasks like preprocessing SASS/LESS files, minifying CSS/JavaScript, linting files, live reloading browsers on changes, and more. It recommends Grunt.js as the most popular task runner with a large community and plugins. The document outlines installing Node.js, Grunt CLI, initializing a Grunt project with a Gruntfile and package.json, installing plugins like Uglify and Watch, and configuring Grunt tasks.