When I talk about microblogging, sometimes I get feedback asking what we should do about cross-site replies. That is, if you’re distributing microblog posts across different domains rather than centralizing them all on a service like Twitter, how do you solve linking together conversations and @-replies across those sites?
I don’t have a solution for that. Of course I’ve thought about it. I wrote 12 years ago about Trackbacks, which were an attempt at solving this. IndieWebCamp has more recent, related proposals.
For my new project, I’ve chosen to just plainly admit that I don’t have a solution for a next-generation Trackback. I will instead have limited centralized replies and favorites. It’s not ideal, but that’s why I call what I’m working on halfway-decentralized. It’s a next step, not the final step.
It’s okay not to solve everything. Cross-site replies and conversations need to come from the community, evolving organically from what people are building with their customized WordPress themes, experimental RSS readers, and new client software for posting. The open web advances incrementally, not all at once, and trying to fight that by tackling too much will get us nowhere.
One of the critiques of RSS feeds in a world dominated by Facebook and Twitter is that RSS just isn’t fast enough. You can’t hope to achieve what Twitter calls “in-the-moment updates” and “watch events unfold” if your client is polling each web site’s RSS feed once an hour for new microblog posts.
Luckily this was solved years ago. Many blogging apps (including WordPress) have a setting to “ping” another server when a post has been published. When it receives this notification, the other server can request the RSS feed and make note of the new post right away.
There are a few flavors of this, such as just passing the URL of the updated feed, or sending an XML-RPC request, or passing the actual post content along with the ping as JSON. It may not be the most efficient or elegant solution, but it works well, and it’s significantly better than frequent polling. You could build something on this.
Some distributed Twitter clones try to come up with something more clever instead. And there are attempts like PubSubHubbub with significant traction. But adopting any new technology is hard, and this ping system is surprisingly well deployed already. Worse is better wins again.