Abstract-In the SEED (Social, Economic and Environmental Development) framework, semantic knowledge management is one of key technologies which refine the framework. In order to facilitate collaborative sustainable development, it is important to know what others are thinking about each other accrues different domains. This paper overviews an ontology exploration tool which facilitates collaborative sustainable development. Its features are divergent exploration according to the user's viewpoints and consensus building support through comparisons among conceptual maps which are results of the explorations.