Sifting through the 200+ starred items in Google Reader I meant to blog months ago. One of the things I’ve always liked about Amazon was the versioned web-service. When they add features or change the structure your old application is still safe, presuming you’ve specified the version your using (I’ve made the mistake of not doing so). Adam Kalsey has a nice short post on versioning Web Services and why it is probably a good idea.

But what happens when something completely changes or an offering completely ends such as the recent change where Yahoo Photo’s closed down in favor of Flickr. There’s a post over at Jeremy Zawodny about decommissioning a web service and the comments are worth reading.

If your library is looking at offering an API or Web Service for patrons or other libraries to build on top of it is probably worth thinking about what will happen when you change things or stop a service altogether. Even if it’s a proof of concept there is a likelihood that someone will end up using it and basing things on it. I’ve found myself getting emails for things I turned off not knowing anyone other than me knew they existed.