The past quarter century has brought about a revolution in front-end electronics for large-scale detector systems. Custom integrated circuits specifically tailored to the requirements of large detector systems have provided unprecedented performance and enabled systems that once were deemed impossible. The evolution of integrated circuit readouts in strip detectors is summarized, the present status described, and challenges posed by the sLHC and ILC are discussed. Performance requirements increase, but key considerations remain as in the past: power dissipation, material, and services. Smaller CMOS feature sizes will not provide the required electronic noise at lower power, but will improve digital power efficiency. Significant improvements appear to be practical in more efficient power distribution. Enhanced digital electronics have provided powerful trigger processors that greatly improve the trigger efficiency. In data readout systems they also improve data throughput, while reducing power requirements. Concurrently with new developments in high energy physics, detector systems for cosmology and astrophysics have made great strides. As an example, a large-scale readout for superconducting bolometer arrays is described.