Knockout

Knockout is a JavaScript library that helps the user to create rich, responsive display and editor user interfaces with a clean underlying data model. Any time the user has sections of UI that update dynamically; Knockout can help them implement it more simply and maintainably, by letting users scale up complexity without the fear of introducing inconsistencies.

With its elegant dependency tracking, it automatically updates the right parts of the user interface whenever the data model changes, and its declarative bindings help construct complex dynamic user interfaces using arbitrary nested binding contexts.

Also, it is trivially extensible, which helps implement custom behaviours as new declarative bindings for easy reuse in just a few lines of code. This three main feature certainly sum to the simple and dynamical way of maintaining user interfaces. Moreover, the user will count with a Pure JavaScript library that works with any server or client-side technology and on any mainstream browser.

It can be added on top of your existing web application without requiring major architectural changes and it has been developed BDD-style, which means its correct functioning can easily be verified on new browsers and platforms. Certainly, another benefit its is size, as it is compact by being around 13kb after gzipping. Another additional feature is that it Works with MVVM technology, a real-time form of MVC with declarative syntax.