This book presents an approach (called OSSS+R) that eases the design of dynamic partial reconfigurable systems based on off-the-shelf FPGAs. An object oriented system description library is extended to allow modeling of such adaptive systems. Reconfigurable hardware is described by means of polymorphism and the concept of virtual hardware. The focus is on quick modeling and flexibility rather than in maximizing the grades of freedom for the design. The models can be simulated to perform functional validation by using a simulation library that is based on SystemC and C/C++. OSSS+R can be automatically synthesized to a RTL model. For demonstration purposes, parts of the transformation are implemented in a tool called Fossy. The generated models are cycle accurate with the original OSSS+R model. The feasibility of the proposed approach is demonstrated by implementing a design as a C++ model and then performing all proposed steps. Finally, the model was implemented on a FPGA prototyping platform.