The aim of this project is to set up a tool composed of * a graphical Modelica editor, aimed at writing the plant model; * an editor for IEC 61131-3 languages (currently, the Ladder Diagram, Sequential Functional Chart and the Functional Block Diagram are being considered), aimed at writing the controller model; * a compiler to turn IEC 61131-3 code into executable code on selected target platforms; * a pre-compiler capable of translating both the plant and controller model in a single Modelica file, to be fed to any Modelica translator for simulation; * an interface to the OpenModelica compiler, for Modelica code parsing, compilation, and simulation; * a simulation output browser. SimForge is fully written in Java (thus crossplatform), uses the XML language as internal data format for maximum openness and transparency, and is entirely free software, released under the terms of the GPL license. It is the authors' intention to allow SimForge to operate with any Modelica compiler, so as to maximise its use and to have the maximum amount of feedback for improvement. Currently, SimForge works with the open source OpenModelica compiler. If you are not interested in IEC 61131-3 controller development, you can still use SimForge as a full-fledged, free, open-source graphical user interface to the OpenModelica compiler.