TntMPD offers a MailChimp sync feature. Due to the complex—and frequently changing—nature of this feature, read these release notes from when the MailChimp feature was first released. Also, search for "MailChimp" in the search box on www.tntmpd.com
http://www.tntware.com/tntmpd/groups/beta_testers/blog/archive/2012/08/29/tntmpd-2-1-r76-beta-sync-with-mailchimp.aspx
