Nat Pryce posted a fun to read summary of software development laws including:

Bram’s Law

The easier a piece of software is to write, the worse it’s implemented in practice. (Bram Cohen)

Gall’s Law

A complex system that works is invariably found to have evolved from a simple system that worked. The inverse proposition also appears to be true: A complex system designed from scratch never works and cannot be made to work. You have to start over, beginning with a working simple system.

Hoare’s Law

Inside every large problem is a small problem struggling to get out.

The Ninety/Ninety Rule

The first 90% of the code accounts for the first 90% of the development time. The remaining 10% of the code accounts for the other 90% of the development time.

See the full list at http://www.natpryce.com/articles/000749.html