#uc is a Firefox extension that allows you to run arbitrary local scripts in chrome windows. In short, userChromeJS + subscriptoverlayloader.js.

###usage Choose script paths and depths in options (Tools -> uc) to autoload according to their meta data block.

• If directory, all *.uc.{js,xul,css} files below it up to specified depth are loaded.
• If depth is 0, the path is ignored.
• The default setting has a single <UChrm> meaning that it loads the chrome directory in your current profile as does subscriptoverlayloader. Note that userChrome.js isn't loaded.

###supported metadata The syntax is roughly identical to Greasemonkey's.

• @name The script name.

• @include / @exclude The URL onto which this script is/isn't loaded.

  • * are wildcards.
  • If prefixed with ~, the rest is treated as regular expression pattern. (example)

• @require Accepts a script URL and loads it beforehand.

  • The URL can be absolute or relative, but must be local.
  • Will not load the same script twice for a window.

• @delay The delay before overlay in milliseconds. XUL only.

• @(whatever) All other meta data are stored simply as text data. UC object defined in each window keeps them.

###improvements from userChromeJS + subscriptoverlayloader.js

• Lets you specify files/directories to load.
• Targets subwindows as well, such as about:config or the sidebar UIs.
• Reads meta data only when necessary--on startup or on script update.
• Regex in @include/@exclude.
• @require

###drawbacks

• Runs on Firefox 3.5+ only.
• Scamps workaround for http://bugzil.la/330458.