Check out pages 71:26 and 71:27 for "Codebase introduction and retention" between Clojure and Scala. I'd like to see more graphics like these to illustrate "lifespan of commits"
I think this can also be problematic. Long lived code _must_ work, which is good. However, it can also live a long time for bad reasons. I have seen long lived code that only lives a long time because it is so complicated that no one can understand how it works, or written in a way that is very hard to change. So it lives a long time, because no one wants to take the time or effort to touch it. Finally, when it _must_ be changed to support a new feature, it might require a full rewrite.
