Simon Willison’s Weblog

Pingback coverage

The Pingback 1.0 specification is getting some serious attention. Mark Pilgrim and Dave Winer have linked to it. Ben Trott (co-author of Moveable Type and creator of TrackBack, the system that inspired Pingback) has objected to Hixie’s suggestion that Pingback is more transparent than TrackBack, claiming that TrackBack could be made just as transparent by the right blog tools. Ben blogged some further thoughts which lead to the following comment by Phil Ringnalda:

I’ve avoided saying anything about PingBack until now, since I like and respect the people who’ve developed it, but it is *not* TrackBack. When you send a TrackBack ping, you are saying “I responded to this, and I think that your readers would also like to read what I said.” You are leaving a remote comment. When you send a PingBack ping, you are saying “I linked to you”, nothing more. It’s a “show referrers” script that filters out non-weblog referrers, a way to avoid having to click your own links to be sure you send a referrer. It is *not* TrackBack.

This is an interesting perspective, but I can’t agree with it completely. Firstly, Pingbacks are meant to be sent by blogging tools. If you have blogged a link to someone else’s entry you are linking to them for a purpose (which is almost certainly some form of comment on their entry)—this is why my Pingback implementation grabs an extract of their page from the text surrounding the link.

michel v has some further thoughts on the differences between Pingback and TrackBack.