Versatility is an important software quality that enables software to serve multiple purposes in a usable and useful way. As such, versatility is central to middleware in general and publish/subscribe infrastructures specifically. The development of versatile software, however, is difficult. It must achieve a favorable balance between different software qualities including: usability, reusability, flexibility and performance, while supports problem domain dependencies and constraints. Developers adopt different strategies in the design of versatile software including: modularization, stabilization, variation, generalization and specificity. By combining these strategies, different infrastructures can be built, for example: minimal core, one-size-fits-all, coordination languages and flexible infrastructures. Each one of these approaches have costs and benefits. 

In this work, we present the results of a multi-dimensional quantitative and qualitative empirical study that analyzes the costs and benefits of existing versatility approaches in the publish/subscribe domain. These results are summarized in the form of guiding principles which goal is to better support application developers in choosing the best design approaches in the development of middleware; and infrastructure consumers in selecting the most appropriate infrastructure to support their applications.