Google has unveiled a "stable" Windows version of Chrome 4.0, providing all PC-based users with access to its new Chrome extension gallery.

Mountain View unveiled Chrome extensions in early December, but until today, they were only available to those running the Chrome 4.0 beta.

Google says the Chrome extensions gallery now includes over 1,500 tools.

Chrome 4.0 is still in beta on Linux and Mac - it's the first incarnation of the browser to be offered for non-Windows machines - and on the Mac, even beta users must wait a bit longer for extensions. At the moment, Google only offers extensions for Windows and Linux.

Google releases Chrome across three separarte "channels": a developer preview channel for testing new features, a beta channel for refining such features, and a stable channel that finally distributes new stuff to world+dog.

The stable Windows version of Chrome 4.0 also offers bookmark sync (for synchronizing your bookmarks across multiple machines) and - according to Google - a 42 per cent performance boost as measured by Mozilla's Dromaeo DOM Core Test.

For developers and designers, Google has added several HTML5 and JavaScript APIs, including the Web SQL database API and the LocalStorage portion of the Web Storage API, which let sites store data on the user's local PC; the Web Sockets API, for sending data over a persistent bi-directional channel; and the notifications API, for serving up alerts onto the browser's status bar.

The Mac beta of Chrome 4.0 lacks not only extensions support but bookmark sync as well. But Google says it's working to bring both features to fanbois "soon."

Typically, once it releases a stable version of its browser, Google automatically delivers the new version to everyone in the stable channel. The company says that the latest updates will happen within the next week. Alternatively, you can manually update your browser on your own