Flat panel display technologies for portable and personal information systems are reviewed. The display sub-system performance requirements, and the metrics for evaluating display technologies for portable systems are discussed. The current display technology choices for high performance portable systems are active matrix liquid crystal display (AMLCD) and field emitter display (FED). AMLCD is at the forefront at an advanced state of development, and it is already in mass production for notebook computer applications. Because of the huge market size, AMLCD technology continues to be developed at an aggressive pace to address the needs of the future portable systems. On the other hand, FED technology is not currently in mass production, but it is being developed at rapid pace; Impressive technology capabilities and demonstration displays have already been shown. This review focuses on the current status and future development trends in both the these display technologies for application to portable systems. The current status of the reflective LCDs and their future development trends are also reviewed.