u.:

This, the first article, is the first published mention of 386BSD. By this time, the project had been operational for 18 months, and William Jolitz was at Berkeley working on the Net/2 release.
In this installment, we discussed the beginning of our project and the initial framework that guided our efforts, in particular, the development of the 386BSD specification.

A UNIX legacy, the "u." or per-process data structure, which held the kernel-related data of a process, was present on 386BSD prior to February 1991.

The "u." in more detail, handling kernel stack overflows in 386BSD.

Anticipating problems allowed us to find flaws in our work. We use the standalone system for bootstrap to load test programs that work machine-dependant portions of the kernel.

Understanding the boundary between research and development with BSD, and where a balance between commercial efforts can be struck.