"Fine, switching to Chrome now," said Dom Diesel. "If you force a Chrome-like design on me ... I can also use the real thing."
Others said they'd give the changes a chance. "It's a little heartbreaking to see the old UI go, but I'll give the new one a shot," said Tom Hunkapiller, a Missouri-based developer.
Australis is currently slated to appear in the production version of Firefox 28, which has a ship date of March 4, 2014, according to recent notes on Mozilla's website. At one point, Mozilla was shooting for Firefox 25, which launched near the end of October.
The Nightly build of Firefox for Windows, OS X and Linux can be downloaded from Mozilla's website.
The new Australis UI (bottom) omits the Firefox menu in Windows (orange in the top image) and fades all inactive tabs into the background.
Sign up for CIO Asia eNewsletters.