Authentication (wiki): who you are.
Authorization (wiki): what you are authorized to do.
(Note the distinction between authentication and authorization (here are here).)
Gist: a simple way to share snippets and pastes with others
Fiddle helps with front-end development (doc)
JS Bin: Fiddle alternative
JsApp.US: hosting platform for node.js app
ideone: online compiler and debugging tool supporting 40+ programming languages., so it can be used for back-end web dev.
Git: SCM tool
Github
BitBucket
Introduction
Comparison
Alternative Client-side MVC frameworks, particularly, Backbone.js, Ember.js, and CanJS
RESTful
References
More
html(ng-app)
Tips & tricks