[JamesFM]

This is highly confusing to me.

If implicit patent grants are a thing, why have more modern licenses like Apache 2 and GPL 3 made it a point to include explicit patents grants in the language of the license?

Wouldn’t their legal counsel advise them against it if it was redundant?

[Fzzr]

Explicit probably saves a lot of time in court, and helps with global consistency. More importantly, Apache 2 and GPL 3 include reciprocal patent grants. They work similarly to the React patent grant, but unlike that one they go both ways. In the React one, only you lose access to the patents if you sue Facebook, but Facebook can sue you fine even if you contributed to React. Under Apache 2 and GPL 3, no one contributing to the software can sue anyone for patents infringed as a result without having their license revoked in its entirety (copyright AND patent).

[Fzzr]

Correction: I'm not sure Apache 2 and GPL work that way. IANAL and please read the licenses yourself (and consult counsel if needed).