Matlab + Simulink is a very powerful tool. This tool allows engineers to simulate real devices. In open sources, some tools exist, such as Scilab + Xcos. With the growing community of Python, some tools appeared: NumPy, SciPy... Those tools intend to propose a Matlab alternative environment equivalent for Python. MuPhyN is an interface that is intended to reproduce the Simulink capabilities. The goal is to produce a community-based simulation software. It is based on a Qt interface and uses a simulator core. It is fully written in Python and uses YAML as the descriptive language. The library feature proposed allows users to add as many boxes and schedulers as they want. The already created boxes take advantage on the SciPy and NumPy libraries to produce their behaviors.