Reinventing the List

Marc Canter seems pretty excited that Songbird is going to support XSPF. While Marc has written about it many times, I had no idea what it was. It’s the XML Shareable Playlist Format (pronounced “spiff”). It’s designed to be simple and open and built on XML. Typically, that’s coolness but while reading the spec, I had a strong sense of deja-vu. XSPF defines a list of songs for a playlist, much the same way that RSS defines a list of blog entries.

So that begs the question, why didn’t XSPF just use RSS instead of starting from scratch? RSS is simple, open, built on XML and is massively popular? Remember when Adam Bosworth that pointed out that RSS and Atom are “both support a base schema that provides a model for sets”. I’m all for a simple, open and extensible playlist format, but I’m not excited that XSPF has gone of an reinvented the concept of “list” in order to do it.

Comments:

Along with a study of existing playlist formats (at http://gonze.com/playlists/playlist-format-survey.html), there was a preliminary study on RSS for this purpose: http://gonze.com/rss_plus_time.html . RSS didn't make sense for a lot of reasons. We were paving cowpaths, and RSS for playlists was very much not a cowpath. Playlists are about sequence, while RSS has no concept of sequence except reverse chronological order. We needed abstractions to deal with the fact that music and movies frequently don't have URLs, and RSS didn't have them. If not starting from scratch was critical, HTML preceded RSS and would be the default to work from. That said, I would have liked for XSPF to be a lot closer to feed formats, even though it didn't work out that way. Maybe in the long run that's the direction it will go.
Along with a study of existing playlist formats (at http://gonze.com/playlists/playlist-format-survey.html), there was a preliminary study on RSS for this purpose: http://gonze.com/rss_plus_time.html .
RSS didn't make sense for a lot of reasons. We were paving cowpaths, and RSS for playlists was very much not a cowpath. Playlists are about sequence, while RSS has no concept of sequence except reverse chronological order. We needed abstractions to deal with the fact that music and movies frequently don't have URLs, and RSS didn't have them. If not starting from scratch was critical, HTML preceded RSS and would be the default to work from.