ABSTRACT
This chapter illustrates measures of the effectiveness of free and open source software (FLOSS) projects. FLOSS is a broad term used to embrace software that is developed and released under either a "free software" or an "open source" license. While the free software and the open source movements are distinct, both kinds of licenses allow users to obtain and distribute the software's original source without charge and to inspect, modify, and redistribute modifications to the source code. The chapter analyzes four possible success measures, namely number of developers, number of mailing list participants, and number of downloads and page views for SourceForge projects in general and for a smaller sample of projects. It makes a contribution to the developing body of empirical research on FLOSS by identifying a collection of success measures that might be applied to FLOSS. The developer community is much more clearly delineated than users, making such a survey feasible.
