# Closure Compiler Documentation

Contents:

- **Closure Compiler Application**
  - [Getting Started](https://developers.google.com/closure/compiler/docs/gettingstarted_app) --- The Hello World of the Closure Compiler application.
- **Advanced Topics and Reference**
  - [Compilation Levels](https://developers.google.com/closure/compiler/docs/compilation_levels) --- Choose the right compilation level for your code.
  - [Restrictions Imposed by the Compiler](https://developers.google.com/closure/compiler/docs/limitations) --- Write JavaScript that works with the Closure Compiler.
  - [Advanced Compilation](https://developers.google.com/closure/compiler/docs/api-tutorial3) --- Achieve better compression rates using the Closure Compiler in advanced compilation mode.
  - [Annotating JavaScript for the Compiler](https://developers.google.com/closure/compiler/docs/js-for-compiler) --- Declare data types for your JavaScript variables to achieve enhanced optimization and warnings.
  - [Externs and Exports](https://developers.google.com/closure/compiler/docs/externs-and-exports) --- Communicating into and out of code compiled with advanced mode.