Robert Szeleney reports that Samba has been ported to SkyOS. Here's his post to the samba mailing list:

I just want to announce that I successfully ported SAMBA without any modifications to SkyOS. If you want to take a look at the small SAMBA configuration utility used to configure SAMBA on SkyOS, you can take a look at http://www.skyos.org

Go check out the SkyOS website. Looks like a nice bit of work. Well done!