"Attosecond light pulses are generated when an intense laser interacts with a gas target. These pulses are not only short, enabling the study of electronic processes at their natural time scale, but also coherent. The vision of this proposal is to extend temporal coherent control concepts to a completely new regime of time and energy, combining (i) ultrashort pulses (ii) broadband excitation (iii) high photon energy, allowing scientists to reach not only valence but also inner shells in atoms and molecules, and, when needed, (iv) high spatial resolution. We want to explore how elementary electronic processes in atoms, molecules and more complex systems can be controlled by using well designed sequences of attosecond pulses. The research project proposed is organized into four parts: 1. Attosecond control of light leading to controlled sequences of attosecond pulses We will develop techniques to generate sequences of attosecond pulses with a variable number of pulses and controlled carrier-envelope-phase variation between consecutive pulses. 2. Attosecond control of electronic processes in atoms and molecules We will investigate the dynamics and coherence of phenomena induced by attosecond excitation of electron wave packets in various systems and we will explore how they can be controlled by a controlled sequence of ultrashort pulses. 3. Intense attosecond sources to reach the nonlinear regime We will optimize attosecond light sources in a systematic way, including amplification of the radiation by injecting a free electron laser. This will open up the possibility to develop nonlinear measurement and control schemes. 4. Attosecond control in more complex systems, including high spatial resolution We will develop ultrafast microscopy techniques, in order to obtain meaningful temporal information in surface and solid state physics. Two directions will be explored, digital in line microscopic holography and photoemission electron microscopy."