Miguel De Icaza recently wrote
To make Linux a viable platform for mainstream desktop use our community needs to realize the importance of these third-party vendors and not alienate them. Having a stable API, and a stable ABI is very important for this reason. GNOME has learned this lesson and has strict commitments on ABI/API stability (thanks to our friends at Sun that pushed for this) and the XFree folks deserve the credit for making ABI compatibility across operating systems a reality for their drivers. Two good steps in the right direction.
This highlights one of the primary differences between amateur and professional software development. To professional software developers words like "backwards compatibility" and "no breaking changes" are words to live by regardless of how painful this can be at times, to amateur software developers they are the equivalent of four letter words that should be ignored in the quest to building something "faster, better and cheaper" than the rest.
An example of this just hit me in RSS Bandit development. I recently released RSS Bandit v1.2.0.42 which added
The ability to store and retrieve feed list from remote locations such as a dasBlog blog, an FTP server or a network file share. This enables users utilizing RSS aggregators on multiple machines to synchronize their feed list from a single point. This feature has been called a subscription harmonizer by some.
Around the time I shipped this release a new version of dasBlog (which is managed by Clemens Vasters) shipped and removed the XML Web Service end points that RSS Bandit was dependent upon for this feature. To see the difference you can compare the ConfigEditingService.asmx from my weblog to the ConfigEditingService.asmx on Torsten's weblog. Note that they are almost completely different. In the space of one release, dasBlog broke a feature in RSS Bandit and any other client that was written to target those end points.
Behavior like this is the bane of the Open Source world that Miguel decried. It's always so easy to change the source code and tell people to download the latest bits that few ever think of the churn they cause by indiscrimnately breaking applications, after all users can always download the newest bits or tweak the code themselves in the worst case.
Instead of finishing up the perf improvements I had in mind for RSS Bandit and working on perf I know have to figure out how to support both dasBlog APIs in a seemless manner without placing the burden on end users. You'll note that both my blog and Torsten's state that they are running dasBlog v1.3.3266.0 even though they expose different XML web service end points which means I can't even expect the user to be able to tell what version of dasBlog they are running with any accuracy.
What a waste of a Sunday evening...