In this demo, we present Genius, a tool that facilitates research in the area of bilateral multi-issue negotiation. It implements an open architecture allowing easy development and integration of existing negotiating agents. Genius can be used to simulate individual negotiation sessions as well as tournaments between negotiating agents in various negotiation scenarios. It allows the specification of negotiation domains and preference profiles by means of a graphical user interface. A number of negotiating agent implementations as well as negotiation scenarios have been collected in Genius. Genius can be used in experiments with human negotiators that negotiate against automated agents or other humans. An analytical toolbox integrated in Genius calculates optimal solutions, such as the Pareto efficient frontier, Nash product and others. This toolbox may be used to visualize a negotiation process and creates an extensive log.