Knowledge personalization is currently the most investigated issue in the context of service-oriented systems. Knowledge representation and management are the subtended critical issues for knowledge personalization, and currently they are largely studied, principally thanks to the explosion of data modelling technologies such as XML and XMLSchema. Despite to some progress, currently, a widely approved standard for delivering knowledge is still missing. In this paper we propose the definition of Distributed Knowledge Networks (DKN), an open framework for delivering personalized knowledge. We also provide a reference architecture for DKN networks.