The GPL is a License, Not a Contract, Which is Why the Sky Isn't Falling

Why isn't it a contract? Because there are no further agreed-upon promises, no reciprocal obligations. It would be a contract if I said to the owner of a pond: if you give me a license to fish in this pond, I'll give you half of all the fish I catch. In that scenario, each of us has voluntarily entered into a kind of promise. We each give the other something of value, so if I get the license and then I don't give over half of all my catch of the day, the pond owner can sue me for not living up to the terms of the contract.

契約書のWHEREAS clauseの後に書くIN CONSIDERATION OF〜って飾りみたいに思ってたけど、ちゃんと生きてる発想なんだね〜。


As a practical matter, copyright holders often raise both types of claims in litigation: breach of contract and copyright infringement. In many of those cases, however, the copyright holder has adopted a software license that is undoubtedly meant to be a contract."