This paper introduces Prometeo a multi-function, modular and extensible proxy server created as part of one the author’s thesis work. We will discuss the needs that this project was meant to address: mainly the lack of an application with the aforesaid features, combined with native IPv6 support and ease of administration. Prometeo also provides a C++ framework which simplifies the development of networking applications. The design of Prometeo’s will be described, starting with an overview of its components and modules and commenting on the most significant parts of the implementation. Then we will focus on the main issues considered during the development of the project, comparing the adopted solutions with those of other state-of-the-art packages like Squid [1]. Finally we will discuss new ways of improving Prometeo’s performances and scalability.