In this paper, an indoor multi-vehicle rapid prototyping platform is designed and implemented to support the development and testing of control and navigation solutions for unmanned aerial vehicles. The hardware architecture devised for the prototyping environment comprises: i) an optical motion capture system providing vehicle position and attitude ground-truth; ii) a set of offboard computers managing communication between systems and running user programs; and iii) multiple quadrotors. In order to provide a vehicle abstraction that hides the specifics of each vehicle and to automate the communication between systems through reliable protocols, a set of software modules were programmed using an object-oriented approach. These modules free the user from implementing low-level flight routines and communication tasks. An additional group of software tools was also created to allow offboard flight logging and monitoring. To enable testing of the deployed algorithms and communication interfaces before experiments with physical vehicles, a fully configurable and easy-to-use simulation environment was also developed. The devised setup allows for a mixed environment of physical and simulated quadcopters, extending testing to conditions that are physically unfeasible at the arena. Finally, several control solutions were deployed and tested, validating the adopted architecture and showcasing its robustness and scalability. The created prototyping platform is a key enabler of future research and education in aerial robotics.