-- In this paper a Rapid Prototyping Framework and next steps towards the support for interactive Architecture Exploration based on the SPEAR processor core (Scalable Processor for Embedded Applications in Real-time environments) are presented. First the Rapid Prototyping Framework is described comprising the System Model Designer, the Hardware Set and the Debugger application. Second our experiences towards realization of two c-compiler ports (GCC and LCC) for our flexible design architecture are revealed, which enable us to perform first steps in Architecture Exploration while creating an overall complete development environment.