gulp.js

var gulp = require('gulp');

// takes in a callback so the engine knows when it'll be done
gulp.task('one', function(cb) {
    // do stuff -- async or otherwise
    cb(err); // if err is not null and not undefined, the orchestration will stop, and 'two' will not run
});

// identifies a dependent task must be complete before this one begins
gulp.task('two', ['one'], function() {
    // task 'one' is done now
});
gulp.task('three', ['two'], function() {
    // task 'two' is done now
});
gulp.task('four', ['three'], function() {
    // task 'three' is done now
});

Par contre tout ce qui est dans l'array va se paralléliser ? Zip et doc vont se paralléliser aussi entre eux ?