Google late last week said it hoped to release versions for Mac OS X and Linux by the first half of the year, and it released a new version Wednesday that paves the way for the most requested feature: extensions.

(Credit: Google)

Google has high hopes for Chrome — in particular, the Internet giant wants better performance, so browsing the web is faster and web-based applications are more powerful. Now Google is filling in some missing pieces Chrome needs in order to attain wider usage. Brian Rakowski, Chrome's product manager, said the company wants to release Chrome for Mac and Linux before the first half of 2009 is up.

"That's what we've been hoping for," he said in an interview. "Those two efforts proceeding in parallel. They're at the same level of progress."

The Mac and Linux versions are up to the level of a basic "test shell" that can show web pages. But a test shell is pretty raw. "That team now is able to render most web pages pretty well. But in terms of the user experience, it's very basic," Rakowski said of the Mac version. "We have not spent any time building out features. We're still iterating on making it stable and getting the architecture right."

In an unscientific CNET News survey from November, a Mac version was the second most common barrier to getting people to switch to Chrome, trailing only faster performance. Eager beavers can monitor Google's Chrome for Mac progress and install the Mac test shell.

Extensions en route
Another major missing piece of Chrome is a framework to handle extensions, optional features that can be downloaded and plugged in to customise the browser. Extensions were one of the early advantages that helped Firefox blossom, it's the top-requested feature for Chrome, and it ranked third in the CNET survey of Chrome barriers.

But a new cutting-edge version of Chrome, 2.0.156.1, gets support for some "Greasemonkey" scripts to customise the browser, a move that lays the groundwork for extensions, Rakowski said.

"We have user script support. That's a baby step," he said. As Chrome develops, Google will "expose more capabilities, then expose containers where can you have your own toolbar-like thing. You'll see it evolve over time."

Google promised an extensions framework when Chrome launched, and more recently, Google outlined its Chrome extensions vision.

Counting Chrome
Google released Chrome 1.0 in December, just three months after the software publicly debuted, and the company is working hard to maintain a fast development pace. Wednesday's version, though not for the general public, is the first to sport the version 2 number.

Also updated with the new version is Google's Chrome release structure.

Before, Google let people subscribe to two Chrome update channels: beta and developer. The first was for relatively well-tested versions; the second for programmers, Web developers, and people with more curiosity and a higher bug threshold.

Now there are three Chrome channels: stable, beta, and developer preview.

Most folks will just use the stable version, which Google expects to update roughly once a quarter, Rakowski said. "The beta channel is now what the developer channel used to be," he added, with newer features but still a reasonable amount of testing. Newest is the developer preview channel, where code will be frequently updated and much more raw, and where Google expects some features to fail and be withdrawn.

Google expects to issue new developer preview versions roughly every couple weeks and new beta releases roughly monthly, Rakowski said.

Major new features
Version 2.0.156.1 includes many new features besides Greasemonkey support. Among them:

• Autocomplete, so Chrome can remember what you've typed into Web forms and enter them again. "A lot of people asked for that. It turns out it's more complicated than it seems on the surface," Rakowski said.
• Full-page zoom, so that using Ctrl+ and Ctrl- to increase or decrease elements on a Web page works better. Before, only text grew or shrank, but now other elements do, too.
• Browser profiles, so you can set up a browser configuration with particular settings such as bookmarks and cookies.
• The ability to import bookmarks from the Google Bookmarks site.
• Autoscroll, so clicking a mouse's middle button, then moving the mouse, lets you slide around larger pages. This is handy for panning around large images without constantly zooming in and out.
• Faster Safe Browsing, a feature to issue warnings about sites that may conduct phishing attacks or other malicious behaviour.
• Under the hood, the update gets a new version of the open source WebKit engine for converting a Web page's descriptive HTML and CSS code into the page displayed on a computer. Chrome's current stable release uses the same WebKit version as is used in Apple's Safari 3.1, but the new Chrome developer preview uses WebKit 528.8, which is faster and supports features such as CSS canvas drawing for 2D shapes such as lines on maps or custom-generated charts.
• An update of Chrome's V8 JavaScript engine from version 0.3.9.3 to 0.4.6.0. JavaScript is used for more elaborate Web pages, and the new version is faster, Rakowski said.

Missing from the new version is support for automatic discovery of Web site subscriptions through RSS and Atom "feed" technology. Google has mapped out feed support; the company plans to add it in the version 2 time frame, Rakowski said.