Stability is a Crutch

I don't think the tension between having good, robust, and bug-free software and having software with new features and capabilities is solvable in the macro case. What follows is a musing on this subject, related in my mind to the On Installing Linux post.

I'm not exactly making the argument that we should all prefer to use unstable and untested software, but I think there is a way in which the stability [1] of the most prevalent Linux distributions is a crutch. Because developers can trust that the operating system will effectively never change, there's no need to write code that expects that it might change.

The argument for this is largely economic: by spacing updates out to once a year or once every 18 months, you can batch "update" costs and save some amount of overhead. The downside here is that if you defer update costs, they tend to increase. Conversely, its difficult to move development forward if you're continuously updating, and if your software is too "fresh," you may loose time to working out bugs in your dependencies rather than your system itself.

The logic of both arguments holds, but I'm not aware of comparative numbers for the costs of either approach. I'm not sure that there are deployments of significant size that actually deploy on anything that isn't reasonably stable. Other factors:

• automated updating and system management.
• testing infrastructure.
• size of deployment.
• number and variety of deployment configurations.