The paper examines requirements for IT support in open innovation within companies. Based on an in-depth single-case study, we derive four major levels of IT requirements: incentive & inspiration, information & knowledge, communication & collaboration, and feedback & feed-forward. The multitude of requirements identified on each level clearly points to the need for IT support during the internal open innovation process. The paper concludes that many findings from prior research on innovation management systems apply to the internal open innovation context as well, but with some interesting differences. An IT system for open innovation within a company should pay particular attention to the incentives and inspiration of employees. The system should motivate all employees to participate in open innovation and stimulate innovative ideas by indicating clear benefits as well as recent needs, challenges and developments in their company’s context. Furthermore, a virtual community seems to be a powerful concept for driving open innovation in the company. It fosters the activity of and the interaction between employees, thereby addressing all of our requirement levels. To build and run such an intraorganizational open innovation community, social software offers useful concepts and applications. Based on the identified requirements, we present initial concepts for their implementation.