Software versioning in which a version is an integer in degrees Kelvin.

Absolute zero is frozen — no further updates are possible. If your Kelvin versions don't track your actual progress, you run out of integers.

If tool B sits on platform A, either both A and B must be at absolute zero, or B must be warmer than A. Whenever the temperature of platform A declines, the temperature of tool B must also decline. Of course, if B itself is a platform on which some higher-level tool C depends, it must follow the same constraints recursively.