D-Ring is a simple web ring script written in PHP4 that allows you to run a web ring on your site, without the need of third party servers, like webring.org or yahoo. D-Ring needs no SQL, and is meant to be easy to install and simple to use.
RingWorld is a CGI script for organizing a WebRing to link together sites featuring the same subject. With RingWorld you can also host your users' WebRings, turning your site into a WebRing server and building your own WebRing community. Users can register their site in any WebRing hosted on your server, or register their own WebRing. Users can also modify personal information or cancel their accounts/WebRings using a special form. RingWorld is available in two different versions: a Perl version and a PHP+MySQL version.