Essential Javascript Design Patterns is a free online book by Addy Osmani about Design Patterns in Javascript. “Design patterns are reusable solutions to commonly occurring problems in software design.”

The patterns covered:

  • Creational Pattern
  • Constructor Pattern
  • Singleton Pattern
  • Module Pattern
  • Revealing Module Pattern
  • Observer Pattern
  • Mediator Pattern
  • Prototype Pattern
  • Command Pattern
  • DRY Pattern
  • Facade Pattern
  • Factory Pattern
  • Mixin Pattern
  • Decorator Pattern

It can be downloaded from Github.