Many people claim that all Spigot plugins have to follow the GPL license. This is a common false statement made by people who have not studied the basics of contract law.
The following text only represents the opinion of the author, who has studied law and is an approved lawyer in Germany as the time of writing this article. Under no circumstances is it guaranteed that the information given here is valid for every country, nor for every time in the future. If you actually need proper legal advice, contact an approved lawyer in your country.
What is the GPL?
To describe it in non-technical terms: The GPL is a special license that allows or disallows a certain party (“the user”) by the the author (“the rightholder”) of such software to use the software under certain conditions using a contract between those two parties.
Small exmapleYou, “xX_PussySlayer69_Xx” has “purchased” a copy of the operating system “Doors 98”. You are “the user”, while the manufacturer of “Doors 98” is “the rightholder” of such mentioned software.
The rightholder of such software will probably have listed a ton of things you are allowed to do with that software, which will typically include stuff like using it.
This is exactly what the GPL does, too. The GPL defines what rights and obligations the usage of such software is given to you by the manufactorer of that software.
What is a contract?
Now it gets a bit more complicated: you have to understand the difference between a law and a mere contract. A contract, in most countries, is nothing more but an agreement between two parties that both promised to stick to. A contract creates, defines and governs mutual rights and obligations among its parties, and to noone else.
“But Bukkit requires plugins to be released under GPL”
While the statement in the above headline might be true, I have to tell you about the privitiy of contracts. While it MIGHT be true, that Bukkit/SpigotMC could enforce the clauses specified in the GPL license, it doesn’t mean that anyone else besides Bukkit/SpigotMC could do so too. A contract is nothing more than an agreement between two or more parties who all agreed to the same clauses. Under no circumstances can someone unrelated else deduce any rights from a contract between other, unrelated parties.
Even if SpigotMC has a contract with Mojang/Microsoft that states that all Bukkit/Spigot plugins must be released under GPL, and even if any plugin author has a contract between themselves and Bukkit/SpigotMC that states that their plugins must be released under the GPL, it does not mean anything to the users of that plugin in question. They do not have any entitlements against the plugin author to release the source of the plugin, or similar things.
“So what can I, as a user of a GPL-violating plugin, can do?”
Sorry, but, let’s be honest – you cannot do anything.
If you have bought a valid license to play Minecraft, you can sue the vendor of that license (probably Microsoft/Mojang) to allow you to play Minecraft. That’s it.
If you bought a Spigot/Bukkit plugin on SpigotMC, you can sue SpigotMC (and/or their representatives) to give you access to that plugin, according to their terms. Which SpigotMC probably did.
What you cannot do is to request the source code of a plugin that you have bought from SpigotMC, unless the author of that plugin told you otherwise.
You are free to report the plugin author to Microsoft/Mojang and/or to SpigotMC, but, and this is the important part:
- The plugin author MIGHT have to provide their source code to SpigotMC
- The plugin author MIGHT have to provide their source code even to Microsoft/Mojang
- But they do not have to provide the source code to you.
If you are person “A”, you can anforce contracts made between person “X” and person “A” and vice versa. But you cannot enforce contracts made between person “X” and person “B” or contracts made between person “X” and person “Z”.