Bukkit

The global scope of your mod is a Context object. Context inherits SandboxContext, so you get all of those members on your global as well.

Every mod has its own Context global, so you don't have to worry about conflicting with other mods. However, if you want to share a JavaScript API, you can assign to the api variable of your global context. This variable is accessible from any mod by calling the mod("mod-name") method of the global context.

It is suggested that you read about the Context object first. If you're eager to get started, you can skip SandboxContext, which is primarily for evaling and sandboxing untrusted code. You may also want to have a look at File.