On the Internet, all sorts of community applications, especially social community applications, gain more and more importance every day. People in every type of community are eager to communicate, collaborate and inform themselves and others about news and information. So far the user interfaces for community applications have been Internet connected computers or advanced smart phones running standard Web browsers. Although, today's mobile technologies and networks offer large sets of context information about mobile users, none of the existing mobile extensions of existing community applications tries to leverage this valuable data. This paper presents an approach to design and architect an IP Multimedia Subsystem (IMS) based Context Aware Mobile Community Application Platform (CAMCAP) that consolidates, federates and processes the most important context data of mobile community users before it provides it to community applications and clients. Furthermore, as proof of concept, this work presents the design and implementation of a University campus community application prototype based on the proposed CAMCAP.