ember

Write dramatically less code with Ember’s Handlebars integrated templates that update automatically when the underlying data changes.
Don’t waste time making trivial choices. Ember.js incorporates common idioms so you can focus on what makes your app special, not reinventing the wheel.
Ember.js is built for productivity. Designed with developer ergonomics in mind, its friendly APIs help you get your job done—fast.

[ember]

Vue

Vue (pronounced /vjuː/, like view) is a progressive framework for building user interfaces. Unlike other monolithic frameworks, Vue is designed from the ground up to be incrementally adoptable. The core library is focused on the view layer only, and is very easy to pick up and integrate with other libraries or existing projects. On the other hand, Vue is also perfectly capable of powering sophisticated Single-Page Applications when used in combination with modern tooling and supporting libraries.

[Vue]

Ionic

Welcome! Ionic is a powerful HTML5 SDK that helps you build native-feeling mobile apps using web technologies like HTML, CSS, and Javascript.
Ionic is focused mainly on the look and feel, and UI interaction of your app. That means we aren’t a replacement for PhoneGap or your favorite Javascript framework. Instead, Ionic simply fits in well with these projects in order to simplify one big part of your app: the front end. We recommend reading Where does the Ionic Framework fit in? to get a good understanding of Ionic’s goals.
Ionic currently requires AngularJS in order to work at its full potential. While you can still use the CSS portion of the framework, you’ll miss out on powerful UI interactions, gestures, animations, and other things.
We will be releasing Cordova/PhoneGap plugins in the future to expand the capabilities of your apps.
[Ionic]

NativeScript for the .NET Developer

Rob Lauer. Telerik Developer Network. 2016-10-26.
Having lived most of my development life inside of Visual Studio, hacking away at mediocre Web Forms apps, it was a shock to my system when mobile-first became the mantra of web development. Add to that mobile app development, and add to that native mobile app development, and you had one lonely and confused .NET developer.
Xamarin may appear to be the logical choice for many .NET developers as I’m afraid they may not be looking past the almighty C#. No knocks on Xamarin here (heck, we offer Telerik UI for Xamarin!), but let’s look at how a free and open source framework can maybe, just maybe, be a better option.

[NativeScript for the .NET Developer]