I wanted to post this to the Mooncoin thread, but I only created my account a few days ago here (although I've been reading the site for a while now) so I can't post to the thread. Looks like the rules require me to post in the Newbies area before I can post anywhere else so here I am.
I don't know why this hasn't been posted to the official Mooncoin thread, but I saw the dev post on Twitter that there are now working wallets for both Windows and Mac OS X. I just downloaded the OS X client and was able to run it on a Mac with Mountain Lion -- haven't tested it on Mavericks yet, but looks good so far.
The official download page for both clients is located here:
http://download.mooncoin.info/Hope that helps.