User Modelling is the core component for the majority of personalisation systems. By keeping a model for every user, a system can successfully personalise its content and utilise available resources accordingly. While researching the literature, one can recognize the importance of achieving interoperability across various platforms and systems while attempting to personalise a large diversity of web resources. Furthermore, scrutable solutions allow users to control any modelling process that uses their information. Finally, privacy of user data while exchanging user models from one source to another must be taken in mind. With this paper, a Scrutable User Modelling Infrastructure is presented which blends together these user modelling ‘ingredients’ and, by adopting Semantic Web technologies, attempts to model a range of life-long user interactions with a variety of web-based systems from the educational, business and social networking domains.