The idea of publishing structured and linked data on the Web started in the early stages of the World Wide Web (WWW) development. The original goal of the Semantic Web is creating a global Web of Data that is machine-readable, or as Tim Berners-Lee described it in his book [8]: “The first step is putting data on the Web in a form that machines can naturally understand, or converting it to that form. This creates what I call a Semantic Web”. The integration of various kinds of data is achieved through the adoption of common conceptualizations referred to as ontologies. Ontologies in different fields, including medicine, biology, climatology, ecology and even e-government, have been created to date. Opening and converting government data to Resource Description Framework (RDF) allows the data to become interlinked, making it a part of Linked Open Data (LOD). In this paper an overview of LOD is given, encompassing the presentation of the realization of LOD, its practical applications and current research trends. LOD is realized through Linked Data principles, HTTP protocol, URIs and RDF links. Its main goal is to identify existing data sets available under open licenses, convert them into the RDF format and publish them on the World Wide Web. Furthermore, state of the art of LOD in e-government is examined and discussed. In spite of a number of successful applications of LOD (like DBPedia or BBC), its ultimate goal has not been fully achieved so far. Further research and development projects therefore still need to be carried out to overcome the existing LOD challenges.