Backbone

Overview:

Backbone is lightweight, flexible and offers a minimalist solution to separating concerns in an application. It is not super opinionated and does not lock a developer into the Backbone way of doing things. Out of the box, the framework supports a persistence layer, RESTful sync, models, views, collections, event-driven communication, templating and routing. Developers are not locked into these constructs and have the ability to provide their own implementations.

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• Flexible. 
• Offers a minimalist solution to separate application concerns.

AngularJS

Highlights:

• Follows Model-View* (see understanding MVVM by Addy Osmani)
  
• Minimal size with about 800 lines of code
• RESTful models
• Simple views (Must provide view-rendering mechanism)
• No impact on server architecture
• No impact on file organization
• Does not need to own the entire page
• Choose your own template engine (String-based handlebars.js is most common).
• Routing (optional - could be interesting but co development with backend side and architecture)

Pros:

• Backbone is incredibly simple, it only has four major components: Collections, Models, Views and a Router.
• Allows developers the ability to easily override parts of the framework to suit custom needs.
• Can leverage extension community to address common problems (i.e., Marionette, Chaplin )
• works fine with jQuery or without
• can handle multiple pages in a single page.
• lightweight

Cons:

• Backbone's documentation on progress real world examples. see jQuery Mobile doc, backbone fundamentals book in progress)
  
• Backbone does not ship with baked-in solutions to common problems ( i.e., Form validation, sub-views and view rendering, etc. ), but could be interesting in a mix approach springMVC / MVVM - couldn't really say for sure depending on springMVC side 's hability to trust and share Css3 and ECMAscript/JavaScript from what I see in France and not to see this as handicraft.
  
• Developers must either provide custom solutions to common problems or adopt a solution from the extension community, but some are already doing this in the real life in spring / jsf development too - do not see any kind of provocation in this on my part.
• While simple at the start, Backbone applications can become very complex and difficult.

Demos:

• TodoMVC : demo: http://todomvc.com/architecture-examples/backbone/ sources: https://github.com/addyosmani/todomvc

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AngularJS

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Knockout

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