Peter Forstmoser was intensively involved in the preparations for the founding and development of Gebert Rüf Stiftung. He has served as Deputy Chairman of the Board of Trustees since the Foundation was established in December 1997. Thus he has played a major role in defining the face of the Foundation from its very beginning.

In his work for the Foundation, Peter Forstmoser considers himself a representative of the legal and social sciences with an interest in interdisciplinary projects. He also seeks to apply his experience as both a scholar and a practitioner. He regards the foundation purpose, that is «to strengthen Switzerland as a place to live and do business», to be the measure of the most promising projects for support.