Knockout vs Ractive

Knockout uses HTML5 data attributes to bind HTML elements to data objects in javascript. This allows more work to be done by the framework rather than requiring you to specify where data should be bound in the javascript. The data binding is very intuitive as the bindings are done within the HTML itself in the location it should be bound.

Has a low entry barrier and an easy learning curve. It's especially easy to learn for beginners.

Bindings in Knockout can also be used to control the generated structure of the HTML. There are bindings provided to allow for iteration and conditionals. The structure of the html reflects the structure of the data so iterative elements are bound to arrays in the data model. Having the HTML structure maintained by bindings keeps the templating simple, easy to read, and maintain.

Knockout also allows for string based templating so you can use whatever templating library you prefer.

Supports a large number of browsers, including IE6.

The excellent tutorials with built-in exercises are a great learning experience, even for people without prior MVVM and data binding experience.

Models in Knockout can be watched to keep the page data up to date by using observable objects. The observables notify Knockout when data is changed and automatically updates the page when this happens. By having Knockout maintain this relation, it keeps the front end code cleaner and simpler, and by enforcing a consistent pattern with observables the methodology can be more robust.

One can do a lot of things and it keeps self references and other types of loops under control.

Knockout does one thing, and does it well. It doesn't try to take on more than one area. It does MVVM data binding and that is it.

Using components is a great way of breaking up large modules into simpler ones.

Ractive.js is a template-driven UI library, but unlike other tools that generate inert HTML, it transforms your templates into blueprints for apps that are interactive by default.

Two-way binding, animations, SVG support and more are provided out-of-the-box – but you can add whatever functionality you need by downloading and creating plugins.

Ractive fully supports a templating language. To be more precise, views are written with a variant of Mustache, which is also extended to support inline JavaScript expressions. Soon it will be able to support other templating languages.

Instead of relying on the DOM, Ractive implements a virtual DOM from scratch, allowing it to calculate precisely what needs to be patched during the next screen refresh. This is orders of magnitude faster than fiddling with the DOM itself.