This article reviews computer applications developed and utilized by industrial-organizational (I-O) psychologists, both in practice and in research. A primary emphasis is on applications developed for Internet usage, because this "network of networks" changes the way I-O psychologists work. The review focuses on traditional and emerging topics in I-O psychology. The first topic involves information technology applications in measurement, defined broadly across levels of analysis (persons, groups, organizations) and domains (abilities, personality, attitudes). Discussion then focuses on individual learning at work, both in formal training and in coping with continual automation of work. A section on job analysis follows, illustrating the role of computers and the Internet in studying jobs. Shifting focus to the group level of analysis, we briefly review how information technology is being used to understand and support cooperative work. Finally, special emphasis is given to the emerging "third discipline" in I-O psychology research-computational modeling of behavioral events in organizations. Throughout this review, themes of innovation and dissemination underlie a continuum between research and practice. The review concludes by setting a framework for I-O psychology in a computerized and networked world.