According to the World of Apple site, Apple has seeded a preview of Safari 4 to developers.
Safari 4 Developer preview is available for Mac OS X Leopard, Tiger and Microsoft Windows.
Safari 4 currently has very few new features but is significantly quicker compared to Safari 3.1 and scores 100/100 in the Acid3 test.
Safari 4 adds the ability to Save a webpage as an application, similar functionality to the third-party application Fluid. Also spotted in the Safari preferences is the ability to specify whether new tabs or windows open with; home page, same page, empty page or bookmarks.
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