I often use Backbone in projects I work on, but I don’t use all the features it has to offer. Backone is quite minimal, but still provides enough functionality to handle pretty complex applications.
The reason I frequently choose to use Backbone is to keep my front-end code tidy and easily maintainable when I create user interfaces. That rarely calls for anything more than two-way communication between models and views. For fun, and to figure out how Backbone works, I decided to make a drop-in Backbone replacement.
My replacement, called Catbone, provides only the features I use when making UIs.
In theory I could use it on all my projects instead of Backbone. It's only 140 lines of code!