In the thesis the concept of semantic web has been studied and its advantages, technology and future development trends presented. A prototype of the application – a data network browser – was made. The browser accepts the ontology, written in the standard RDF language, via SPARQL queries and visualizes the information obtained. It also allows searching and filtering for specific entities and their properties. The visualization is interactive and the displayed graph can be explored further. The implementation of the application is based on the HTML5 markup language and various JavaScript libraries which help with the visualization of graphs and other functionalities. Data for the demonstration of the prototype was obtained from a database g...