The state of the art of ultrafast Er:fiber technology is reviewed. Such lasers are increasingly used for generation of ultrabroadband and widely tunable pulse trains. Er:fiber sources prove to be flexible, compact and robust with important applications in fundamental and interdisciplinary sciences. After a short overview of different oscillator and amplifier designs the discussion focuses on coherent and tailored supercontinuum generation in highly nonlinear germanosilicate fibers. This approach enables a tuning range spanning from the visible to the mid infrared, synthesis of single‐cycle light pulses and passive locking of the carrier‐envelope phase.