gulp-system-sample.js

//for a dynamically loaded application
// <script src="system.js">
// <script src="system.config.js">
// <script>
//   System.import('app');
// </script>

//for a prebuilt app
var Builder = require('systemjs-builder');

//bundle task
gulp.task('bundle', function(){
  var builder = new Builder();
  
  //returns a promise
  return builder.loadConfig('./system.config.js')
    .then(function() {
      // ready to build
      // returns a promise
      return builder.buildStatic('app', 'dist/app.js');
   });
});