Trello.com - technologies used

From http://adamgent.com/post/10225284147/trello-from-fogcreek-using-nodejs - 

• Nodejs for Webserver 
• Express for MVC
• JQuery
• Backbone
• SocketIO
• JQueryUI

 It's all written in Coffee Script as well. Mongo stores our permanent data, and we're using Redis as a transient data store.


From http://stackoverflow.com/questions/5053167/backbone-js-versus-express-versus-ext-js-and-jspp - 

backbone.js is a client-side MVC framework.

JSPP is a means you can write inline server-side code (like PHP or ASP) for nodejs

Express is a node.js specific server-side framework for web development.

Ext JS is a framework for making web applications and widgets.

There all very different. There isn't any point in a direct comparison without you telling us what you want to use them for.

To vaguely answer your question. IMHO I would say using backbone.js on the client and on nodejs is great for MVC centric design.

Express is a great layer of abstraction on nodejs because it beats writing the code yourself. Use it to serve content to your clients.

Ext JS is not free.

JSPP looks like ASP/PHP!