Mozilla on Wednesday released an updated version of its browser command-line tool Ubiquity.

Ubiquity allows Firefox users to open a command window and type commands that execute a series of actions, like a macro or script might do. For example, the command email [message content, if any] to [username@domain.com] launches the user's e-mail client and populates the appropriate data fields with the specified address, message, and URL for the Web page active at the time the command line was invoked.

Ubiquity was released in August; the new version, Ubiquity 1.5, is faster and more stable, according to Mozilla. It includes command memory and command matching that functions similarly to the Firefox 3 "Awesome Bar." Version 1.5 also adds the ability to use CSS skins to alter the appearance of the user interface.

"Anyone can now give Ubiquity a new look," explains Aza Raskin, head of user experience at Mozilla Labs, in a post on the Mozilla Labs blog. "It's as simple as a little bit of CSS. That's how the new look was created! Once you've created a skin, it's easy to share it with the world: You can subscribe to skins just like you can subscribe to commands."

Since Ubiquity first appeared, the Firefox user community has been busy coding commands for Ubiquity. Users can subscribe to the Ubiquity Herd Command Feed, a sort of RSS feed for Ubiquity commands. Its aim is to make commands more discoverable, and it does so by adding the "herd" command.

Entering the "herd" command in the Ubiquity window launches a Web page with command code contributed by the Firefox community. The user is then free to subscribe to individual commands, like "word-count," "translate," or "facebook-status."

Subscribing to the Ubiquity Herd, however, isn't for the faint of heart. The first time you try it, you're presented with the following security warning: "You are about to subscribe to a Ubiquity command from an unknown, untrusted third-party source at http://ubiquity.mozilla.com/... . If you subscribe, this command could do anything it wants to your browser. It could steal your credit card number or e-mail your grandmother your entire image browsing history."

Those with grandmothers, and even those without, may not feel comfortable ignoring that warning.