Dedicated to Bart :)
First time I saw growth rings of the tree I have been told that they reflects its age. Each year the new ring is appearing so, you can easily calculate how long this tree stands there. As simple as that, life of an any software product could be traced by its version numbers. Just unlike the tree, the software has multiple branches of "growth" (or evolution): functional, maturity and so on. Actually every company has its own versioning approach, different identification of stages. But versioning is always incremental and usually do not require more then 3 numbers.
