JavaScript parser, mangler/compressor and beautifier toolkit

 UglifyJS is a JavaScript compressor/minifier written in JavaScript. It
 also contains tools that allow one to automate working with JavaScript
 code:
 .
  * A parser which produces an abstract syntax tree (AST) from
    JavaScript code.
  * A code generator which outputs JavaScript code from an AST, also
    providing the option to get a source map.
  * A compressor (optimizer) - it uses the transformer API to optimize
    an AST into a smaller one.
  * A mangler - reduce names of local variables to (usually)
    single-letters.
  * A scope analyzer, which is a tool that augments the AST with
    information about where variables are defined/referenced etc.
  * A tree walker - a simple API allowing you to do something on every
    node in the AST.
  * A tree transformer - another API intended to transform the tree.
 .
 All the above utilities and APIs are defined in ~6500 lines of code
 (except for the effective generation of the source-map, which is
 handled by the source-map module). Compared to alternatives, UglifyJS
 is pretty small.