It's definitely Mac-centric. Mac in all the screenshots. Mac link in the menu has a blue border to make it stand out and the Windows one doesn't. Like you said,

It's definitely Mac-centric. Mac in all the screenshots. Mac link in the menu has a blue border to make it stand out and the Windows one doesn't. Like you said, the bottom of the homepage is a link to download the Mac version. Release notes are all for Mac, no Windows. The blog talks about "Fork", which is a Mac app, and then a separate "Fork for Windows".