Safari is Apple’s web browser for OSX. It has replaced IE as the default Mac browser, and Microsoft has suspended development on the IE for Mac project.
Safari is proprietary, however it was built on the open source KHTML project. Over time, Safari has diverged substantially from that base.
Matt Mullenweg throws out some stats for wordpress.com; it's clear they still have to support IE6. In regards to questions about the wisdom of 37signals, I wonder if their audience isn't less IE-heavy in the first place.
server logs... That number breaks down as 577 million users of Internet Explorer, 38 million of Firefox, 17 million of Safari, and 5 million of Opera. Lots m