Bower is a package manager for the web originally created at Twitter and adopted by a large community.

It offers a generic, un-opinionated solution to the problem of front-end package management. It exposes the package dependency model via an API that can be consumed by a more opinionated build stack. There are no system wide dependencies, no dependencies are shared between different apps, and the dependency tree is flat. Bower runs over Git and is package-agnostic. A packaged component can be made up of any type of asset and use any type of transport.

It is also included in the Yeoman project.