The technical capacities of service offers for e-government and e-participation have considerably progressed over the last years. Yet, the principles of good governance are still not well implemented, especially when it comes to policy development. Governments struggle to effectively apply innovative technologies in regards to providing open collaboration in policy formulation or to monitor and evaluate policy implementation. Through a recent initiative of the European Commission (EC), several research projects have been launched to address these challenges. This paper first investigates existing deficiencies in open government towards transparent policy development. Subsequently, an approach of a project funded by the EC is introduced to develop better ICT support for open collaboration in policy modeling. The approach combines existing e-participation tools, collaborative scenario generation and formal policy modeling to evaluate and explore policies via agent-based modeling (OCOPOMO - www.ocopomo.eu).