High harmonic generation opens the way towards attosecond pulse generation. Single attosecond pulse generation requires not only intense, reproducible few-cycle drive pulses, but also a control of the carrier phase with respect to the pulse envelope (i.e., the carrier envelope offset, CEO). Until recently the only successful demonstration of CEO-phase-locked intense pulses in the near infrared (IR) was based on a CEO stabilized Ti:sapphire laser, chirped-pulse amplification and pulse compression in a hollow fiber. Meanwhile, there are some new promising ways to achieve this goal. One is based on chirped pulse optical parametric amplification (CPOPA) and the other on pulse compression through filamentation. During this talk pulse generation in the few-cycle regime, CEO stabilization, and CEO-controlled filament self-compression will be reviewed which resulted in pulse durations as short as 5.1 fs to date. Such pulses have been used in combination with our new COLTRIMS apparatus to measure the intensity distribution in momentum space of He, ionized with intense circularly polarized 5.5 fs IR pulses. The measurement (Fig. 1) shows a clear dependence on the pulses carrier—envelope phase.