Bundler for ___?

What is the bundler equivalent for your various development stacks? I'm really getting into rails and I appreciate how much easier it is to add and remove libraries/gems . When I was learning Java however, finding and managing libraries was a pain, and there'd be no chance I'd scour the internet for an updated version down the line. I understand that Maven is a thing, but that led me to wonder what other development stacks use for this same purpose. Other than Bundler, Maven, and node.js's npm, I'm unaware of any. I've also dabbled in game development with Unity3d, and the situation there is even worse, most of the libraries I find are one file of code, and make no mention of dependency management.