How does the Apache License 2.0 handle patents?

The Apache License 2.0 addresses patents by explicitly granting contributors’ patent rights to users while including safeguards against patent litigation. When a contributor submits code under the Apache License 2.0, they automatically grant a royalty-free, irrevocable patent license to anyone using the software. This license covers any patents owned or controlled by the contributor that are necessarily infringed by their contributed code. For example, if a developer contributes a module that implements a patented algorithm, users of that module are protected from patent claims related to its use within the licensed software. This provision ensures that contributors cannot later sue users for patent infringement based on their own contributions, fostering trust in open-source collaboration.

The license also includes a patent retaliation clause to deter litigation. If a user initiates patent litigation against any party over the licensed software, their rights under the Apache License 2.0—including patent grants—are terminated. This applies even if the lawsuit targets code unrelated to their own contributions. For instance, if a company uses Apache-licensed code in their product but later sues the project’s maintainers over a separate patent, the company loses all rights to use the software. Termination is automatic and applies only to the party filing the lawsuit, not to downstream users. This clause discourages aggressive patent enforcement while protecting the community from legal threats tied to the software’s use.

Finally, the Apache License 2.0 clarifies that contributors are not required to license all their patents, only those directly tied to their contributions. This prevents contributors from unintentionally exposing unrelated patents. For example, a company contributing a networking feature under Apache 2.0 grants rights to patents covering that specific feature but retains control over patents in other areas, like graphics processing. Additionally, the license allows sublicensing, ensuring downstream users receive the same patent protections as the original licensee. Compared to licenses like GPLv3, which impose broader patent conditions, Apache 2.0 strikes a balance by protecting users without overburdening contributors, making it a pragmatic choice for projects prioritizing both innovation and legal clarity.