Recent activities of governments around the world regarding the publication of open government data on the Web, re-introduced the Open Data concept. The concept of Open Data represents the idea that certain data should be freely available to the public, i.e. the citizens, for use, reuse, republishing and redistributing, with little or no restrictions. The goal is to make non-personal data open, ... [Show full abstract] so that it can be used for building useful applications which leverage their value, allow insight, provide access to government services and support transparency. These data can contribute to the overall development of the society, by both boosting the ICT business sector and allowing citizens a deeper insight into the work of their government. This recent rise in interest for Open Data introduced the necessity for efficient mechanisms which enable easy publishing, management and consumption of such data. Therefore, we developed an Open Data Portal, with the use of the technologies of the Semantic Web. It allows users to publish, manage and consume data in machine-readable formats, interlink their data with data published elsewhere on the Web, publish applications build on top of the data, and interact with other users.