Open source, Science and Commerical Interests

We are committed to providing excellent open source software

The LIGGGHTS® and CFDEM®coupling simulation engines are open source, and will stay open source!

CFDEM®project is operating on the interface of open source software, science and physical modelling, mechanical and chemical engineering, and many other disciplines. After a journey over a couple of years, we made quite some thoughts about how to bring these ingredients together in the best way - to maintain and to grow CFDEM®project in a way that balances the interests of all stakeholders. We think there are two main ingredients for open source projects: Idealism and funding.

We are acting based on the following principle:
Those who give idealism, should get idealism in return, those who give funding, should get monetary value in return.

Ingredient 1: Idealism

An open source project needs other open source projects
CFDEM®project would never exist without the possibility to use other people's codes, most notably the OpenFOAM® project and the LAMMPS project. Of course, we also heavily rely on many other open source projects. Following our principle, the usage of other's work implies the obligation for us to give back open source code to that can be used freely by everyone. This is what we do: CFDEM®project releases LIGGGHTS®-PUBLIC and CFDEM®coupling-PUBLIC to the open community.

An open source project needs a community
To really "live" as an open source project, a vivid community is needed, which is connected through discussions, community contributions, and workshops. Please see here for how you can get involved!

The community contributions will strengthen the open source, CFDEM®coupling-PUBLIC and LIGGGHTS®-PUBLIC versions which are freely available to the community! In a nutshell, following the Free Software Definition, a program is free software if the program's users have the four essential freedoms:

  • The freedom to run the program as you wish, for any purpose (freedom 0).
  • The freedom to study how the program works, and change it so it does your computing as you wish (freedom 1). Access to the source code is a precondition for this.
  • The freedom to redistribute copies so you can help your neighbor (freedom 2).
  • The freedom to distribute copies of your modified versions to others (freedom 3). By doing this you can give the whole community a chance to benefit from your changes. Access to the source code is a precondition for this.

Ingredient 2: Funding

An open source project needs funding

This is one of the points which is very often misunderstood. Please don't get us wrong, but open source projects can't live from idealism alone. They also need strong and stable funding in order to prosper.

The Free Software Foundation says about selling free software:

  • “Free software” does not mean “noncommercial”
  • “'Free software' means software that respects users' freedom and community. ... Thus, 'free software' is a matter of liberty, not price”
  • “To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'. We sometimes call it 'libre software' to show we do not mean it is gratis.
  • See here for more info.

To get where CFDEM®project is now, companies from all around the world, as well as public funding agencies, have spent several million Euros for developing features, code and models, and delivering services around CFDEM®project. We try to give those who give funding some monetary compensation in exchange. We are realizing this via LIGGGHTS®-PREMIUM and CFDEM®coupling-PREMIUM: Company A would find it very irritating if they invested €50,000 into a new feature for LIGGGHTS® or CFDEM®coupling and company B (competitor of company A) could download it right away the next day. For this reason, some of the features are "locked in" for industrial sponsors of CFDEM®project for some time, and after some time they finally go into LIGGGHTS®-PUBLIC and CFDEM®coupling-PUBLIC. The Premium versions are made available to industrial partners and customers as part of a long-term collaboration involving development projects to further strengthen the model portfolio of CFDEM®project.


We all at CFDEM®project are looking forward to continue our efforts to provide excellent open source software in fluid mechanics and particle science. We're looking forward to the challenges ahead and are happy for everyone who joins us on this way!

If you have any feed-back on this statement, please contact us.