Following its initial release in June of this year, Apple has seeded the second build of Windows and Mac OS X web browser Safari 4.

The developer preview labelled 40A12 is available for Mac OS X Leopard, Tiger (4A08) and Microsoft Windows.

The latest version of Safari is likely to include many of the features of Webkit and has reportedly included SquirrelFish technology which provides JavaScript speed ups.

It is currently unknown as to when Apple intends to release Safari 4 to the public.