
Safari is Apple's Web browser. It's one of the more speedy browsers around, and it was one of the first Web browsers to introduce a built-in RSS reader. It's currently in its third iteration and recently went cross-platform--leaving its Mac-only status and adding the ability to work on Windows, too.
Safari began as an in-house replacement to Microsoft's Internet Explorer for Mac, which Microsoft didn't update or improve on at the same rate as as it did for its Windows counterpart--and eventually dropped shortly after the release of Safari.
Safari has recently gotten quite a bit of attention for its inclusion as the default Web browser in Apple's iPhone