Caedium!

Xcos is a graphical editor to design hybrid dynamical systems models. Models can be designed, loaded, saved, compiled and simulated.

Simulink is a platform for multidomain simulation and Model-Based Design of dynamic systems. It provides an interactive graphical environment and a customizable set of block libraries that let you accurately design, simulate, implement, and test control, signal processing, communications, and other time-varying systems.

Minsky enables the simulation of models (particularly from economics) defined in terms of coupled ordinary differential equations. The models are defined using a drawing canvas (rather like VisSim), and a double entry bookkeeping system known as a Godley table.

VisSim™ is a visual language for modeling and simulating nonlinear dynamic systems. With 9 integration methods, 4 optimization methods and over 200 vector and scalar block functions.