Popular videos and articles get reposted or discussed on dozens or hundreds of sites. But Web experts are now thinking about how to keep track of online conversation in real time, even when it's scattered all over the Web. A new crop of protocols aim to do just that.
The protocols provide notifications when new content is available, rather than passively waiting for search crawlers or feed readers to discover the content. For example, pubsubhubbub, an extension to the protocols used today to syndicate content, can push content out to feed readers as it's updated. Building on that Salmon, a protocol first proposed last month, could allow comments to "swim upstream" to connect to the original post, regardless of where they're made.

Technologies like this are needed for today's Web, where content tends to flow from one site to another, said Kevin Marks in a keynote given last week at Defrag 2009, a technology conference in Denver focused on tools and technologies for handling online data. Marks cofounded Microformats, a set of standards for social information on the Web.