An improved JavaScript mode for GNU Emacs.

Features:

• variable (adjustable) indentation
• accurate syntax highlighting
• highlighting of syntactic errors and many semantic errors
• strict-mode warning reporting (such as duplicate var declaration)
• smart line-wrapping in comments and strings
• typing helpers (e.g. matching quotes/brackets)
• code-folding (collapse element as {...})
• supports JavaScript 1.5, 1.6 (including E4X), 1.7 and 1.8
• customizable colors, or use font-lock defaults
• many customization options

Note - this mode is for GNU Emacs, version 22 and higher. It does not support XEmacs.