Open Source

Open Source Software

Current analyses show that today’s software solutions consist on average of 70% open-source software, also called “free software” (FOSS). In addition to the modularisation of software development, the decisive factor here is the user-friendly licensing model that grants comprehensive rights of use for any purpose. However, the simple and licence-fee-free access to programs and libraries does not mean that the licensee has no obligations to observe.

In particular, when distributing one’s own products with open source components, licence obligations must be observed, the violation of which is regularly accompanied by copyright infringement.

We support you both in enforcing open source licences and in advising you on the licence-compliant distribution of your products.

Open Source Licence Compliance

The use of open source components in one’s own software products requires a careful examination of copyright and licensing requirements.

In practice, many software products contain numerous open source components – mostly libraries – that are subject to different licence conditions, or that individual software packages themselves combine code that is subject to different open source licences

For appropriate licence compliance, the soft-ware must be analysed to ensure that all licence conditions are adhered to.

One focus here is on checking licence compatibility and the question of whether in-house developments are subject to the copyleft due to the concrete software architecture used and must be released as open source.

Here, we have many years of experience in the preparation of expert opinions and in consulting, especially in the Linux environment for embedded systems as well as for Eclipse and Java solutions.

In cooperation with a specialised technical service provider (Tjaldur Software Governance Solutions), we offer the following services:

  • Implementation of in-house open source com-pliance systems that comply with the international standard ISO/IEC 5230:2020 (OpenChain)
  • Scan of source code to analyse licence information and check licence obligations and licence compatibility
  • Analysis of the source code used for the binary code of the own product.
  • Checking third-party components in the object code for open source components
  • PExamination of the licence compatibility of the open source licences used and creation of checklists for compliance with licence obligations when distributing the software
  • Necessity of releasing own developments under an open source licence
  • Creation of a company-wide open source compliance policy
  • Audits to check the open source compliance of processes and products


In due diligences in the IT environment, the examination of the open source licensing situation plays an important role, as it is highly relevant for the evaluation of software-based products. This applies both from the buyer’s and the seller’s point of view. We have many years of experience in conducting open source due diligences and also cooperate with law firms specialising in M&A that do not want to offer this area themselves.


The GNU General Public License (GPL) is an important licence for Free Software and has been the subject of several legal disputes. The use of GPL software, especially in combination with proprietary in-house developments or pro-grams under other open source licences, requires a careful prior analysis of the so-called “copyleft”.

Copyleft is the obligation to redistribute soft-ware derived from a GPL program only under the licence conditions of the GPL. This can lead to complex questions of consideration as to which components must be licensed under the GPL and which must not. Here we have many years of experience in legal assessment.

Open Chain

We are a recognised partner of the Open Chain Project, which has established an international standard for open source licence compliance (ISO/IEC 5230:2020). Here we have participated in the development of the specification, contributing our many years of experience.


The GPL has been enforced in several court cases before German courts. Those who have released their developments as open source software can demand compliance with the licence conditions or prohibit further use of the software.

Enforcement of open source licences is often also possible out of court, especially in cases where the licence infringement was inadvertent. We are happy to represent your rights as an author.

But also for users, compliance with open source licences by competitors can be of interest in order to enable fair competition with the provider who is in compliance with the licence.

Increasingly, mass demand letters are being issued for Creative Commons licences as well as GPL and LGPL. Here we defend you to protect you from unjustified claims.

Contributions and own Open Source Projects

The use of open source licences for own devel-opments can be a competitive tool. The choice of a suitable open source licence is crucial for the planned business model.

In practice, various licensing models have emerged, ranging from parallel licensing as proprietary software and open source software (so-called dual licensing) to the partial release of proprietary developments. Here we support you in analysing the options under licensing law.