Bower vs Duo: What are the differences?

Bower: A package manager for the web. Bower is a package manager for the web. It offers a generic, unopinionated solution to the problem of front-end package management, while exposing 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; Duo: A next-generation package manager for the front end. Duo is a next-generation package manager that blends the best ideas from Component, Browserify and Go to make organizing and writing front-end code quick and painless.

Bower and Duo can be primarily classified as "Front End Package Manager" tools.

Some of the features offered by Bower are:

• Bower operates at a lower level than previous attempts at client-side package management – such as Jam, Volo, or Ender. These managers could consume Bower as a dependency.
• Bower's aim is simply to install packages, resolve dependencies from a bower.json, check versions, and then provide an API which reports on these things. Nothing more. This is a major diversion from past attempts at browser package management.
• Bower offers a generic, unopinionated solution to the problem of package management, while exposing an API that can be consumed by a more opinionated build stack.

On the other hand, Duo provides the following key features:

• has first-class support for Javascript, HTML and CSS
• exposes a unix-y command line interface
• pulls source directly from GitHub with semantic versioning

Bower and Duo are both open source tools. Bower with 15.2K GitHub stars and 1.97K forks on GitHub appears to be more popular than Duo with 3.52K GitHub stars and 145 GitHub forks.