Using open-source code such as GPL in products: Open-source it per the license or switch licenses — don’t treat this as “no one cares”

Cost: There is no cost involved. Before using someone else’s open-source code, check its license for any stated usage terms. The GPL family of licenses requires that any product built using it must also have its source code released, which conflicts with selling the product as closed-source software for profit. If such a conflict exists, you must switch to another license. The hard part is giving up a library you’ve already grown comfortable using.

In plain terms: Copyright infringement requires you to compensate the copyright holder based on their actual losses or the profits you earned from the infringement. If you commit infringement intentionally and under aggravating circumstances, you may be ordered to pay damages ranging from 1 to 5 times the original amount. One company hired a former employee of a competitor and developed software that was substantially similar to the competitor’s product. The company argued that since the competitor’s software used GPLv2, it was required to be open-source anyway. The Supreme People’s Court ruled that whether a developer complies with GPLv2 or not has no bearing on their copyright rights, and ordered the company to cease infringement and pay 500,000 yuan in damages.

Benefit: Copyright infringement demands compensation based on the rights holder’s actual losses or the infringer’s profits. If neither of these can be accurately calculated, damages are determined by how much it would cost to obtain a proper license for the same software. Intentional and aggravated infringement can also result in 1 to 5 times the standard compensation amount. If the infringement harms public interests, any illegal profits may be confiscated and fines imposed. A relevant official case is Supreme People’s Court Civil Appeal No. 51 of 2021. In this case, a defendant hired a former employee of a plaintiff and developed gateway software that was substantially similar to the plaintiff’s product. The defendant claimed the plaintiff’s software used GPLv2 and thus should have been open-source. The Supreme People’s Court reiterated that compliance with GPLv2 and copyright ownership are two separate issues, and ordered the defendant to cease infringement and pay 500,000 yuan in damages nationwide.

Evidence grade: B

Sources:全国人大常委会 (2020). 著作权法（2020 年修正，第五十三、五十四条）. http://www.npc.gov.cn/npc/c2/c30834/202011/t20201119_308796.html；最高人民法院知识产权法庭 (2022). 涉「开源软件」著作权侵权案（（2021）最高法知民终 51 号）. https://ipc.court.gov.cn/zh-cn/news/view-3042.html

Notes: This case makes it clear that “the other party used GPL code” cannot serve as justification for copying their software. Conversely, there are already effective court rulings in China where GPL authors successfully sue commercial entities that fail to release source code. No original text of these rulings could be found on the Supreme People’s Court website, so they are not cited here. This item is graded B because compliance with open-source licenses is governed only by general contract and copyright laws, without any specific legal provisions dedicated to this area.