Ultralink is a project I've been working on that aims to improve and move forward the most basic of internet grammars: the link. I have tried to figure out solutions to all the problems that hyperlinks have like staleness/broken links, overlinking, authoring/maintenance labor intensity, single resource restriction, etc. In attacking those problems, I also stumbled across a lot of other really neat features and value additions that you get when you add an abstraction layer to links.
I have made some products that are aimed at consumers, like the browser extensions and WordPress plugin that anybody can just use to kick the tires. These hook into something I call the Mainline Database which is a gigantic repository of Ultralinks meant for use in general contexts. I think of it as a kind of long-term, Wikipediaesque public service that anybody can use for free to do content analysis, public sentiment analytics or other interesting stuff.
I have also tried to make the platform as open and extensible as possible so that developers can build on top of the technology and use it in solving their own problems. I have documented many aspects of how the technology works and made some tools you can play around with on the developer site: https://developer.ultralink.me. Feedback here would be especially useful from the Hacker News community.
I'm happy to answer any questions you might have or discuss ideas for where to take Ultralink going forward :)