This paper is about oral reading fluency, how it has been measured, the students who have been measured, and the outcomes that have been reported for both performance and progress. This measurement system has almost become ubiquitous with documentation of response to intervention in reading and become a focal point of research on reading. Fluency is one of the 'Big Five' skill areas identified by the National Reading Panel and provides an accessible target for both researchers and practitioners. In the course of 30 years, oral reading fluency has been administered in the field in a relatively standard manner, though the reading passages and populations associated with its use, as well as the manner for analyzing results, have varied. In the end, the results are remarkably consistent, both in levels of performance and rates of progress.