OpenData.sk as an initiative to promote the dissemination of data emerging in the public sector and improving its quality and availability. Conceptual, methodological and technological challenges of technical solutions. Different approaches and strategies for data harvesting, the pursuit of sustainability - aggregation vs. federated approach. Ways of improving the quality and quantity of public data. Contextualization and aggregation of information and internal coherence. Crowdsourcing and collaborative approach to public data services. Tools and potential applications on quality and up-to-date data.