Google reveals Chrome extensions plan

Google has published its plan to build into Chrome what is arguably its most requested feature: the ability to accept extensions that can customize how the open-source Web browser operates.

And guess what? Google's dependence on advertising notwithstanding, one of the extension examples the company points to is the ability to block advertisements.

The Chrome extensions document, spotlighted Saturday by Google programmer Aaron Boodman, doesn't include a timeline, but it does shed light on why the project is a priority for Chromium, the open-source project behind Chrome.

"Chromium can't be everything to all people," according to the document. "User-created extensions have been proposed to solve these problems: the addition of features that have specific or limited appeal; users coming from other browsers who are used to certain extensions that they can't live without; bundling partners who would like to add features to Chromium specific to their bundle."

When Google launched Chrome three months ago, it promised a Chrome extensions framework. Extensions are a popular feature of Chrome's most likely rival, Mozilla's Firefox, and one very popular extension is AdBlock Plus.

And AdBlock makes a specific appearance on the list of extension uses that Google said it would like to support eventually:

• Bookmarking/navigation tools: Delicious Toolbar, StumbleUpon, Web-based history, new tab page clipboard accelerators.

• Content enhancements: Skype extension (clickable phone numbers), RealPlayer extension (save video), Autolink (generic microformat data--addresses, phone numbers, etc.)

• Content filtering: AdBlock, Flashblock, privacy control, parental control

• Download helpers: video helpers, download accelerators, DownThemAll, FlashGot

• Features: ForecastFox, FoxyTunes, Web Of Trust, GooglePreview, BugMeNot

Demand for extensions is real.

In an unscientific CNET News poll about why people don't use Chrome, about 19 percent pointed to the lack of an extensions feature. And on Google's issue tracking site for Chromium, a Chrome extensions feature is the top-requested item.

"Of all the Firefox plug-ins, this is the one essential one," said Firefox user Ole Eichhorn. "Chrome is faster until you factor in all the cruft that gets downloaded as ads, then it isn't faster anymore. When Chrome supports AdBlock, it will be the winner, but until it does, Firefox is the only choice."

In its document, Google described some of its goals for Chrome extensions. The extensions should silently update, just like Chrome does. They should be isolated for security reasons and only get access to resources it's entitled to use. Installation should be easy, taking only two clicks.

They should permit rich user interface options--rich enough to implement some parts of Chrome as extensions, Google said. Among the interface options should be "toolbars, sidebars, content scripts (for Greasemonkey-like functionality), and content filtering (for parental filters, malware filters, or AdBlock-like functionality)," Google said. Some interfaces will require the user to grant specific permissions, such as "access to the history database" or "access to mail.google.com," Google said.

Google will play a major role in extensions, providing a central service that can be used to issue updates and to blacklist "malicious or harmful extensions" so the browser won't use them.

"It's likely in the future we may want to provide a consumer front-end which would allow users to more easily find the most popular, highest quality and trustworthy extensions," Google also said.