Software rot

Software rot (bit rot, code rot, software erosion, software decay, or software entropy) is the degradation, deterioration, or loss of the use or performance of software over time.

From a software user experience perspective, it is operating environmental evolution inclusive of hardware. The first cause for the objective loss to the practical use of software is the loss of the host system as a practical operating environment.

The Jargon File, a compendium of hacker lore, defines "bit rot" as a jocular explanation for the degradation of a software program over time even if "nothing has changed"; the idea behind this is almost as if the bits that make up the program were subject to radioactive decay.^[1]