Apple released Safari on Windows when a majority of Windows users were still using IE7. It was a genuine play for a pie of the Windows browser market and its search revenue. It had nothing to do with web apps. When it happened, Jobs positioned its release as a way to make Safari even better, since more people would use it and report issues and bugs.
“We think Windows users are going to be really impressed when they see how fast and intuitive web browsing can be with Safari”, said Steve Jobs, Apple's CEO. “Hundreds of millions of Windows users already use iTunes, and we look forward to turning them on to Safari's superior browsing experience too”.
History demonstrates that actually they didn't and Apple gave up quickly.
Interestingly they also have some benchmark
> [Safari] now it's the fastest browser on Windows, loading and drawing web pages up to twice as fast as Microsoft Internet Explorer 7 and up to 1.6 times faster than Mozilla Firefox 2 (*)
but by reading the more we learn that they benchmarked Safari on a Mac and the other two browsers on a Windows machine.
