Framer.js is a prototyping tool that helps quickly building complex interactions and rich animations.

Framer.js aims for performance above all, as well as simplicity, stating that the framework is “targeted at designers that can do basic JavaScript, up until experienced interface programmers.”

You can style everything with JS or CSS. The view system is neatly structured with layers acting almost like views.

GruntStart is a Grunt task for building optimized websites with the HTML5 Boiler Plate, jQuery, Modernizr, and more.

GruntStart keeps track of the file changes and automatically optimizes what you’ve written. It has all of the required libraries included, so all you have to do is download it from GitHub and zap away!

Centurion is a responsive web framework that scales with the user’s device.

Among Centurion’s remarkable qualities and features are ease of use, performance efficiency as well as a responsive layout that’s completely integrated with several libraries such as jQuery, CoffeeScript, Craydent and more.

The grid used by this framework is rather straightforward, thus making prototyping with Centurion rather easy.

Ozone Widget Framework (OWF) is a government-developed lightweight widget framework.

The idea behind this framework is that it’s actually a web application that you deploy on your server where it’s used for developing widgets.

OWF works on most modern browsers, including IE7. The widgets themselves are decentralized and ran inside of iFrames, allowing for cross-domain interaction.

HTML5 Bones is a “back to basics” HTML5 template for people who want to start writing code just with the bare minimum of prerequisites.

HTML5 Bones omits the use of JS libraries such as jQuery and JavaScript, but does strive to provide at least some browser support, namely, for IE versions 8 and below.

The framework includes only Normalize.css nad html5shiv so size isn’t much of a concern here.

Pomelo is a Node framework for building scalable game servers.

Pomelo comes with an all-powerful API and allows achieving a scalable architecture with almost no extra code. 

Actually something like this should’ve been built quite long ago, as if you think about it Node has one of the best environments there can be for building an MMO.