tl;dr:Software should be (1) robust, handling edge cases, various user inputs (2) Reliable, working for an extended period of time "under design conditions," and outside those conditions too. (3) Stable, not changing in unexpected ways. (4) Simple enough to meet the other 3 goals, nothing more.
tl;dr:C clearly stands out as the "single most important and influential programming language." However, as you work with other languages a tension arises - "you’re stuck either writing bad C code or using poorly-suited tools to interface badly with an otherwise good API."
tl;dr:Two types of changes in open source software inflict trauma on communities. A change where everyone has to overhaul their code to get it to work again, or a change to get code idiomatic again. Drew shows examples of both of these in the Python community.
tl;dr:Drew manages releases for free & open-source software, and consistently found ways of making a new mistake each time he shipped a release. Here he shares those mistakes to prevent them from recurring.