gulp-atcss 
AtCSS - Annotations based CSS processor
$ npm install --save-dev gulp-atcssvar gulp = require('gulp');
var atcss = require('gulp-atcss');
gulp.task('default', function () {
return gulp.src('src/app.css')
.pipe(atcss())
.pipe(gulp.dest('dist'));
});The MIT License (MIT)
Copyright (c) 2014 Masaaki Morishita