"Reference Links" allows custom Urls to be attached to nodes. Its use is seen basically for documentation pages on a site.
This module allows users to add links (internal or external) to nodes, that can provide further information about the current node. The important thing is that Users need NOT have edit permissions for the node. You can allow users with non-edit permissions to add/attach new links to nodes, when the page is being viewed normally.
Moreover, authorized users can also rate the links (this module uses Voting API for the rating part), and links are always shown in decreasing order of their average rating. All actions are performed via Ajax, and no page refresh is required.
If I try to summarize it, this module can provide a References/See also/Bibliography kind of links for nodes. You can control which content types you want the urls to be attached to.
Starting with version 6.x-1.2, the module now supports configurable Voting widgets. You can currently choose between a Star Rating widget (similar to the 5-star module), or an Up/Down Rating widget (similar to the 1-Plus module). More configuration options like allowing users to change votes is also supported now.
An online demo for this module is now available here.