Google has made good on its promise and has released developer-only versions of its Chrome browser for Mac and Linux, nine-months after it first launched the Windows version of the browser.

The Mac and Linux versions are rough and unstable, warned Google. "We have early developer channel versions of Google Chrome for Mac OS X and Linux, but whatever you do, please DON'T DOWNLOAD THEM!" said Mike Smith and Karen Grunberg, a pair of Chrome product managers, in an entry to a Google blog. "Unless of course you are a developer or take great pleasure in incomplete, unpredictable, and potentially crashing software."

The new versions lack important features and functionality, Smith and Grunberg warned, including compatibility with Adobe's Flash Player plug-in and printing. A current bug list catalogues other missing pieces, ranging from a working bookmark manager - users can bookmark pages, but there's no way to retrieve a bookmark - to a memory leak.

Google launched Chrome back in September last year, as a Windows-only browser, but began taking names for a notification list for Mac users that same day, and for Linux users shortly after.

Chrome accounted for approximately 1.8 percent of those used last month, according to the most recent data from web metric company Net Applications, a surge of 27 percent from the month before.

On Windows, Chrome comes in three flavours: Google's developer, beta and stable versions, in ascending order of fit and finish. Google releases more developer preview builds than betas, which in turn accumulate until the company's satisfied with their progress enough to roll out another stable build.

"[We're] trying to get Google Chrome on these platforms stable enough for a beta release as soon as possible!" added Smith and Grunberg.

Although the two program managers acknowledged that the developer preview crashes, Techworld's sister title, Computerworld US, ran the Mac browser for several hours without a hitch.

Both the Mac and Linux editions can be downloaded from Google's site.