GLOSSARY . DEFINITION
What Is Dual Licensing?
Dual licensing is when the copyright holder offers the same software under two different licenses and lets the user choose which to take. Commonly one option is a copyleft open source license with reciprocal obligations, and the other is a paid commercial license that removes them. For enterprises the key point is plain: the code is identical, but which license you accept decides what you owe.
Definition
Dual licensing is a distribution model in which a single body of software is made available under two separate licenses at the same time, and the recipient picks one. Only the copyright holder can do this, because only the holder has the right to set the terms on which the code is offered. The two options usually pull in different directions. One is a recognized open source license, frequently a copyleft license such as the GPL or the GNU AGPL, which is free to use but carries reciprocal obligations. The other is a commercial license, paid, which grants the same software without those obligations. The user who can live with the copyleft terms takes the open option at no cost. The user who cannot, often because they ship proprietary product or run a service that would trigger the obligations, pays for the commercial option instead.
Why it matters to enterprises
Dual licensing matters because the choice of option is a commercial decision that often gets made by accident. An engineer adopts the free open source version because it is the path of least resistance, without checking whether the company's distribution or service model can actually satisfy the copyleft obligations attached to it. Months or years later, the product ships or the service goes live, the obligation that the open option carries is now in play, and the only clean exit is the commercial license the vendor was selling all along. By then usage has grown, leverage has shifted to the vendor, and the commercial license is priced against a position the company walked into without noticing. The risk is not the model itself, which is legitimate. The risk is treating the free option as obligation free.
What to check in your own estate
Three checks settle most dual licensing questions. First, identify which option you are actually using for each dual licensed component, because the free and paid versions can be indistinguishable in the artifact while differing entirely in the terms. Second, test whether the open option's obligations bite given how you distribute or serve the software, since a copyleft obligation that never triggers leaves you free to stay on the open option. Third, decide deliberately rather than by default, so that if the commercial license is the right choice you negotiate it from your real usage numbers rather than under pressure. A dependency map that records the license option and the use model for every component, dated because this area moves quickly, turns these into clear answers. Dual licensing is closely related to source available licensing and to the open core model, and more terms are defined in the open source license risk glossary.
This definition is commercial and licensing risk context, not legal advice. For interpretation of a dual licensing arrangement against your specific use, engage your own counsel.
COMMON QUESTIONS
Questions buyers ask.
What is dual licensing?
Dual licensing is when the copyright holder offers the same software under two different licenses, and the user chooses which to take. Often one option is a copyleft open source license with reciprocal obligations, and the other is a paid commercial license that removes those obligations. The same code, two sets of terms.
Why do vendors use dual licensing?
Dual licensing lets a vendor build adoption through a free open source option while selling a commercial license to companies that cannot accept the copyleft obligations. It works because only the copyright holder can relicense the code, so a competitor cannot offer the same paid exemption. It is a common monetization model for open source projects.
Is dual licensing the same as open core?
No. Dual licensing offers the same code under two licenses. Open core ships an open source base and reserves additional features for a paid proprietary edition. With dual licensing the difference is the license terms, while with open core the difference is the feature set. Many vendors combine both models.
What should enterprises check about dual licensed software?
Which license you are actually using, whether the open option's obligations bite given your distribution or service model, and whether your use would push you toward the commercial license. The risk is adopting under the open option, triggering copyleft obligations you cannot meet, and then facing a commercial license priced against that position.
CONTAINMENT
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