SDM-Doc is a nice open source tool for documenting system dynamics models. The latest version runs in Java and provides new functionality. See the Workbench for a link:

SDM-Doc/Java

The Java version provides a superset of the .NET capabilities (expect for the display of stock and flow diagrams). Among the additional capabilities are:

• Feedback Loop Information
• Feedback Loop and Link Polarity Information
• Results stored in single html file
• Language support for: English, Spanish, French, German, Italian, Portugese, Japanese

SDM-Doc/Java (ver 1.0.4, Mar 14, 2015) was developed to provide the documentation capabilities of SDM-Doc/.NET but without the requirements of having Vensim installed on the computer and running .NET on a Microsoft Windows PC. The tool reads the MDL file and parses the equations and graphic data to gather all data required for dcoumentation.