64-bit Firefox variant Waterfox 16.0.1 has been released, providing Windows users with a stable version of Firefox that’s optimised for 64-bit systems.

The latest build finally appears 19 days after Firefox 16 itself was released, and includes all the changes and improvements found in the 16.0.1 build of Firefox. However, it has already been effectively made out-of-date by the appearance of Firefox 16.0.2, which contains a critical security fix.

Waterfox 16.0.1 contains all of the new features introduced in Firefox 16.0.1, including initial support for web apps, performance improvements based on incremental garbage collection and a new Developer Toolbar. This latter feature includes buttons for quick access to developer tools, plus a new command line for quick keyboard access and recently opened files list for Scratchpad.

The latest build of Waterfox doesn't contain the security fix recently added to Firefox 16.0.2.

Users can also discover which tabs are consuming most memory in Firefox by typing about:memory into a new tab, while several CSS3 features – including animations and transitions – have been unprefixed, recognising the fact they’re now stable. Like Firefox, the inline PDF viewer is present but hasn’t been switched on due to ongoing development – you can trial it manually with the help of our guide.

Waterfox 16.0.1 also drops the AVG Security Toolbar, which was briefly added to version 15’s installer as an optional add-on in an attempt to help support Waterfox’s development. A largely negative response led to its quick removal.

Unlike Firefox, there’s no built-in updating yet implemented in Firefox – instead users are prompted to launch the updater tool manually with the /checknow parameter added to its shortcut.

Despite the delay, the new build is already out of date, after Mozilla released Firefox 16.0.2 FINAL, which contains a single critical security fix – see here for full details – that we presume will lead to the quick release of Waterfox 16.0.2. In the meantime, for those who can’t wait, Waterfox 16.0.1 is a freeware download for PCs running a 64-bit version of Windows.