Why Copyright Analysis Alone Is Not Enough for Open Source Licensing – Open Source Guy

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Why Copyright Analysis Alone Is Not Enough for Open Source Licensing

Published by

Shuji Sado

on

July 13, 2026

Where Japanese IP Advice Can Miss Contracts, Corporate Practice, and Community Norms

I regularly receive requests for advice on the use of licenses, primarily Open Source licenses, and often have occasion to provide my own interpretation. In doing so, I sometimes refer to the interpretations and views of outside experts. However, I do not often find those interpretations convincing. In particular, I frequently feel that explanations and advice from Japanese intellectual property lawyers are somehow subtly off the mark.

This is not to say that Japanese lawyers in general have this problem. I am well aware that there are excellent scholars and practitioners, particularly in the field of copyright law. However, when matters extend to Open Source, Source Available licenses, and terms governing AI models, explanations confined to Japanese copyright doctrine increasingly fail to address what is required in practice. As a result, the gap has become more noticeable in a growing number of situations.

To understand this gap, Open Source-related licensing needs to be considered through at least three layers. Layer 1 is the legal analysis of copyright licensing and infringement. Layer 2 concerns contractual issues arising from license conditions and terms of use. Layer 3 is the practical business assessment, including corporate operations, global compliance, community relations, and reputation. My sense is that the gap in much Japanese IP commentary arises mainly when conclusions are reached at Layer 1 without adequate consideration of Layers 2 and 3.

Layer 1: Copyright Licensing and Infringement

Traditional software licenses are first analyzed in terms of copyright permissions and the legal issues arising from acts such as reproduction, adaptation, distribution, and public transmission. Even with the GPL, questions such as whether particular code constitutes a derivative work, whether distribution has occurred, and whether there is an obligation to provide Corresponding Source belong primarily to the copyright layer. In this respect, interpreting the relevant issues under Japanese copyright law is naturally important.

For use by a Japanese company, it is necessary to examine rights such as reproduction, adaptation, and public transmission under Japanese law. The point is not that such analysis is wrong. The problem arises when that analysis alone is treated as sufficient to determine whether the company should ultimately permit the use.

Layer 2: Contracts and Terms of Use

Modern licensing practice cannot be adequately addressed through copyright licensing and infringement analysis alone.

Since *Artifex v. Hancom*, this issue has received particular attention, at least in the United States. Even a license such as the GPL raises not only the question of whether its conditions operate as conditions of copyright permission, but also the question of how its contractual character should be understood. If a violation of license conditions may give rise not only to copyright infringement but also to breach of contract, the analysis cannot stop with copyright law.

With terms governing AI models such as Llama and Gemma, an explicit contractual and terms-of-use layer sits on top of the copyright layer. Where the terms incorporate use restrictions, redistribution conditions, an Acceptable Use Policy, commercial-use restrictions, restrictions on the development or improvement of other models, governing-law provisions, forum-selection clauses, or obligations to delete materials upon termination, assessing only whether there is copyright infringement under Japanese law is insufficient for enterprise risk analysis.

Even if a particular use is permissible under copyright law, a company is not necessarily free to proceed if the use may violate contractual restrictions. Conversely, doubts about the enforceability of a contractual provision under Japanese law do not make it safe for a company simply to disregard it. Practical risks remain, including suspension of use by the vendor, termination, deletion demands, account suspension, and the burden of responding to a dispute.

The same is true of so-called Source Available licenses such as the Server Side Public License (SSPL). The fact that source code is visible does not mean that the software can be treated as Open Source. The source may be available, but it is not necessarily free to use in the same sense as Open Source software. Use in a competing service may be subject to onerous conditions, and offering the software as SaaS may trigger broad source code disclosure obligations. In other words, source availability and freedom to use are separated.

If the analysis focuses only on whether the source code has been published or how far copyright...