Emacs mode for editing Javascript programs

 This JavaScript editing mode supports:
 .
  - the full JavaScript language through version 1.7
  - support for most Rhino and SpiderMonkey extensions from 1.5 to 1.7
  - accurate syntax highlighting using a recursive-descent parser
  - syntax-error and strict-mode warning reporting
  - "bouncing" line indentation to choose among alternate indentation points
  - smart line-wrapping within comments and strings
  - code folding:
    - show some or all function bodies as {...}
    - show some or all block comments as /*...*/
  - context-sensitive menu bar and popup menus
  - code browsing using the imenu' package
  - typing helpers (e.g. inserting matching braces/parens)
  - many customization options