A very interesting robotics area is the high-level tasks' specification, and the way a user-robot interface can facilitate programming complex actions to be executed on real environments. This paper shows a novel contribution in the user-robot interaction domain, and particularly in the web robotics field. The user, who is in the control loop, is able to specify the robot actions over a simulated scenario (running off-line), assisted with 3D virtual and augmented reality. Then, once the task is defined, it can be easily executed over the real scenario (running online). To get its main goal (i.e. task specification) working in real life scenarios, the system incorporates automatic object recognition and visually-guided grasping among others capabilities.