Knockout vs Aurelia

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.

Full support for Typescript built in

Clear, intuitive and HTML/SVG compliant binding syntax.

Examples:

Default binding => value.bind

One Way binding => value.one-way

Two Way binding => value.two-way

One Time binding => value.one-time

Configured to give you the most common use cases by convention, which means you only need to change the default configuration for edge cases. This means that for normal cases far less boiler plate code has to be written.

Aurelia includes native support for ES6 and even comes with a Gulpfile which helps with transpiling ES6 code to ES5.

Aurelia is extremely unopinionated and was designed to be highly modular. This gives the developer the freedom to develop their application however they want, without forcing them in paradigms or rules predefined by the framework. Likewise, any of the individual components can be swapped out if so desired.

Aurelia developers always try to keep within existing and emerging Web Standards, making it easier for developers to follow best practices in web development.

Most of the code you write is Aurelia-agnostic. It's one of the closest libraries that you'll find to basically write plain-old, vanilla Javascript or TypeScript code (classes) and doesn't polluate your HTML/SCSS. That way you can easily test it, switch to another implementation and make it look clean (business oriented). Even the HTML.

Learning aurelia basically means learning EcmaScript and HTML, since aurelia is designed for standards compliance. Also, aurelia embraces upcoming ES language features by convention, such as ES class decorators for dependency injection, encouraging clean architecture and future-proof code.

The syntax used to bind variables within the application class is very similar to Javascript itself. You can specify the type of the binding you are using explicitly, which practically self-documents your code and makes it easy to understand whether a value is one-way or two-way binded.

Aurelia.js consists of modules that can be used as a full framework or separately.

One of the most crucial pieces of any new technology or framework is the documentation. At present even though Aurelia is pre-beta, the documentation is pretty complete. There are code examples missing and whatnot, but for the most part it is concise and makes the main parts of the application easy to understand.

Aurelia is officially backed by Durandal Inc. and has commercial and enterprise support is available.

Aurelia defaults to one-way data binding, alining with conventional wisdom. However, there are times when two-way data binding proves useful, such as binding an input widget with a view-model. Aurelia makes two-way data binding available to developers and uses it by convention when appropriate.

Aurelia can be used alongside of React and Polymer, since it is designed for interoperability. In practice, this means Aurelia developers can use React components by including an Aurelia custom element:
https://github.com/Vheissu/aurelia-react-example/blob/master/README.md

It also works well with Polymer, since they are both based on the WebComponents standards:
http://aurelia.io/hub.html#/doc/article/aurelia/framework/latest/integrating-with-polymer

https://github.com/aurelia/cli
The CLI helps rapid creation of projects with generators, building, deploying and hot reloads. Webpack should be coming soon.

The Aurelia community is growing at a great pace. Still doesn’t rival the big players line Angular or React, but the answer to an Aurelia issue is a quick question away on their Discourse.

With dependency injection, you can load in extra javascript and new functionality just when you need it.

This is particularly helpful with testing as you can swap out services for test services.

It also means in single page apps you can load dependencies only as you need them instead of loading them up all up at the start.