Open Source License

The MIT and Apache 2.0 licenses permit commercial use and closed-source modifications, the GPL requires derivative works to also be open-sourced, and the AGPL requires open-sourcing even when software is provided as a service over a network.

In the absence of an explicit license, code is protected by copyright by default, and others have no right to copy, modify, or distribute it.

Open-source models are typically released under Apache 2.0, MIT, or custom licenses that allow commercial use and modification, and operate under a different regulatory framework from hardware export controls.

The open-source licensing mechanism is built on top of the copyright system, using the exclusive rights granted by copyright law to achieve open sharing; if copyright were completely abolished, licenses such as the GPL would lose their legal effect.

LLM training data often contains large amounts of open-source code, and generated content may imperceptibly reproduce copyrighted fragments, bringing legal risks to projects.

For secondary development, priority should be given to the license type (MIT/Apache 2.0 are permissive, GPL is copyleft), community activity, and maintenance frequency.

Open-source licenses cannot counter national-level import bans or procurement restrictions.

Open weights means the model parameter files can be downloaded publicly, but it does not mean they can be used freely; it and open-source licenses (such as Apache 2.0 and MIT) are two different concepts.

Open-source licenses, by granting the rights to view, modify, and redistribute code, turn vendor lock-in risk from a commercial promise into a legal guarantee.

Having access to model weights does not imply the right to commercial use, redistribution, modification, or training of derivative models; one must read the license for that specific model and its variants.

Evaluating whether an open-source model can be used commercially requires checking the license text clause by clause, especially user scale limits, prohibited uses, and redistribution terms, as the term 'open-source' alone does not legally mean free commercial use.

Even if an open-source project mentions third-party licenses in its README, it still needs to add a license to the repository/project itself to cover its own original code.

A robust license review and attribution mechanism should be established when using third-party open-source code.

Open-source licenses give the community the fallback capability to continue a free version through forking