I’ve just installed Alan J Castonguay’s Wordpress OpenID plugin on my blog, part of a cleanup that included nuking 11000+ comments in the moderation queue using the Spam Karma 2 plugin. Apologies if I zapped any real comments too. There are a few left, at least!

The OpenID thing appears to “just work”. By which I mean, I could log in via it and leave a comment. I’d be super-grateful if those of you with OpenIDs could take a minute to leave a comment on this post, to see if it works as well as it seems to. If it doesn’t, a bug report (to danbrickley@gmail.com) would be much appreciated. Those of you with LiveJournals or AOL/AIM accounts already have OpenID, even if you didn’t notice. See the HTML source for my homepage to see how I use “danbri.org” as an OpenID while delegating the hard work to LiveJournal. For more on OpenID, check out these tutorial slides (flash/pdf) from Simon Willison and David Recordon.

Thinking about OpenID-mediated blog comments, the tempting thing then would be to do something with the accumulated URIs. The plugin keeps its data in nice SQL tables and presumably accessible by other Wordpress plugins. It’s been a while since I made a Wordpress plugin, but they seem to have a pretty good framework accessible to them now.

mysql> select user_id, url from wp_openid_identities;
+---------+--------------------+
| user_id | url                |
+---------+--------------------+
|      46 | http://danbri.org/ |
+---------+--------------------+
1 row in set (0.28 sec)

At the moment, it’s just me. It’d be fun to try scooping up RDF (FOAF, SKOS, SIOC, feeds…) from any OpenID URIs that accumulate there. Hmm I even wrote up that project idea a while back - SparqlPress. At the time I tried prototyping it in Redland + PHP, but nowadays I’d probably use Benjamin Nowack’s ARC library, which provides SPARQL query of a MySQL-backed RDF store, and is written in PHP. This gives it the same dependencies as Wordpress, making it ideal for pluginization. If anyone’s looking for a modest-sized practical SemWeb project to hack on, that one could be a lot of fun.

There’s a lot of interesting and creative fuss about “social networking” site interop around lately, largely thanks to the social graph paper from Brad Fitzpatrick and David Recordon. I lean towards the “show me, don’t tell me” approach regarding buddylists and suchlike (as does Julian Bond with Ecademy), which is why FOAF has only ever had the mild-mannered “knows” relationship in the core vocabulary, rather than trying to over-formalise “bestest friend EVER” and other teenisms. So what I like about this Wordpress plugin is that it gives some evidence-based raw material for decentralised social networking apps. Blog comments don’t tell the whole story; nothing tells the whole story. But rather than maintain a FOAF “knows” list (or blogroll, or blog-reader config) by hand, I’d prefer to be able to partially automate it by querying information about whose blogs I’ve commented on, and vice-versa. There’s a lot that could be built, intimidatingly much, that it’s hard to know where to start. I suggest that everyone in the SemWeb scene having an OpenID with a FOAF file linked from it would be an interesting platform from which to start exploring…

Meanwhile, I’ll try generating an RDF blogroll from any URIs that show up in my OpenID Wordpress table, so I can generate a planetplanet or chumpologica configuration automatically…