Geoinformation deployed over the Internet is characterized by a high level of diversification: many different formats, systems, and services, offered by public and commercial suppliers. Interoperability of the services and of data is gaining increased importance.

In this presentation OpenLayers, a freely available mapping client is presented, where the emphasis is explicitely placed on the integration if different services and formats. The organisational framework conditions of this project may be considered to be exemplary with regard to other successful projects of this category. It is demonstrated how data can be loaded, integrated, and visualized.

A general tendency is increasing convergence of open data and freely available software tools; this will be demonstrated with the example of OpenStreetMap, a project of high importance for developed and developing countries