Siconos is an open-source scientific software primarily targeted at modeling and
simulating nonsmooth dynamical systems in C++ and in Python:

* Mechanical systems (rigid or solid) with unilateral contact and Coulomb
  friction and impact (nonsmooth mechanics, contact dynamics, multibody systems
  dynamics or granular materials).
* Switched Electrical Circuit such as electrical circuits with ideal and
  piecewise linear components: power converter, rectifier, Phase-Locked Loop
  (PLL) or Analog-to-Digital converter.
* Sliding mode control systems.
* Biology (Gene regulatory network).

Other applications are found in Systems and Control (hybrid systems,
differential inclusions, optimal control with state constraints), Optimization
(Complementarity systems and Variational inequalities), Fluid Mechanics, and
Computer Graphics.