Vue is designed from the ground up to be incrementally adoptable, the core library is focused on the view layer only, and is easy to pick up and integrate with other libraries or existing projects.
Angular is an application design framework and development platform for creating efficient and sophisticated single-page apps.
Svelte is a radical new approach to building user interfaces. Whereas traditional frameworks like React and Vue do the bulk of their work in the browser, Svelte shifts that work into a compile step that happens when you build your app.
Backbone.js gives structure to web applications by providing models with key-value binding and custom events, collections with a rich API of enumerable functions, views with declarative event handling, and connects it all to your existing API over a RESTful JSON interface.
Fast 3kB alternative to React with the same modern API .Preact provides the thinnest possible Virtual DOM abstraction on top of the DOM. It builds on stable platform features, registers real event handlers and plays nicely with other libraries.