The computational power provided by current general purpose computers allows to undertake the implementation of low cost software-only real time audio processors. Unfortunately, computational power is not the only requirement for high demand applications. There are still important difficulties to overcome in other areas such as robustness and low latency. These difficulties have lead us to the development of Rappid, a development framework for C++ real-time high-demand audio processing applications. This paper describes the Rappid development framework. First of all we discuss the objectives we pursue with its development, and we give an overview to some other existent solutions before starting the actual description of the framework. We finally describe a first sound processing application which has been successfully developed with it.