When I visit the site, it just says, "Coming soon." It appears that you can order a CD through PayPal, but the website says, "Boycott PayPall." My impression is that they want you to pay for it. I'm also concerned that it is not actually ready, so they will take your money and hang you out to drive.
I think the versions before 1.0 were available. You may find a site that has mirrored the older versions.
At this time, more information is available at
http://gnu-darwin.sourceforge.net/download.php