FMI Library

FMI Library (FMIL) is a software package written in C that enables integration of Functional Mock-up Units (FMUs) import in applications. FMI Library is an independent open-source implementation of the FMI open standard ( The library provides a C API for interacting with all parts of FMUs, including unzipping, loading of shared object files (DLLs) contained in FMUs, as well as parsing of XML model metadata files. The user is thereby relieved from managing the details of FMU interaction, which significantly reduce the time required to implement FMU import capabilities.

FMI Library is suitable in contexts where FMUs need to be integrated in existing applications or in custom software projects. 

Key features:

  • Full support for FMI for Model Exchange and Co-simulation 2.0 in FMI Library 2.0
  • Full support for FMI for Model Exchange 1.0
  • Full support for FMI for Co-simulation 1.0
  • A unified C API encapsulating all parts of the FMU interaction, including ZIP, DLL and XML management
  • Build system based on CMake, enabling generation of native build scripts (MSVC on Windows, GCC on Linux and Mac)
  • Extensive API documentation in HTML format

FMI Library is the basis of the official FMI Compliance Checker ( provided by the Modelica Association.

Note that FMI Library 2.0 and forward is backward compatible with the 1.0.1 release. It supports both FMI 1.0 and 2.0 specifications and contains a number of bug fixes as compared to the 1.0.1.


The source code is available from the Subversion server at

Source Windows binaries  Release date 2012-08-30 2012-10-18 2013-06-20 2013-08-26 2013-12-20 2013-12-20 2014-08-21 2014-10-28 2016-03-23 2016-09-26 2016-09-30 2017-10-05 2017-11-06



FMIL is licensed under the BSD license.