<p>Decompositional methods of system analysis are considered for optimizing interactive geoinformational services (IGISs) through synergetic integration, consolidated cooperation, and adaptation to various domains, problems, and data. Key mechanisms of IGIS evolution (energetic, informational, network, genetic, communicational, and operational) are defined, which form a comprehensive strategy for their development. An ontological system of IGIS interaction within domain clusters is proposed, which provides a semantic basis for joint solution of complex problems. In accordance with the INSPIRE paradigm, a model of transdomain infrastructure of geospatial data is developed, which increases the interoperability of services to the web medium. The efficiency of IGIS cooperation is shown in an example of optimizing emergency service routes in a megalopolis using game theory.</p>