Open Source in Web-Based Applications: A Case Study on Single Sign-On

Business and recreational activities on the global communication infrastructure are increasingly based on the use of remote resources and services, and on the interaction between different, remotely located parties. In such a context, Single Sign-On technologies simplify the log-on process allowing automatic access to secondary domains through a unique log-on operation to the primary domain. In this article, we evaluate different Single Sign-On implementations focusing on the central role of Open Source in the development of Web-based systems. We outline requirements for Single Sign-On systems and evaluate four existing Open Source implementations in terms of degree of fulfilment of those requirements. Finally we compare those Open Source systems with respect to some specific Open Source community patterns.