Anatomy of Blink

A talk I gave at NEU Wireless Club, comparing implementations of the "hello world" hardware equivalent — the periodic LED blink — in Assembly, C, C++, and Rust.
Most Arduino tutorials take the IDE as a given. This makes sense for ease of use, but what is really behind those "Verify" and "Upload" buttons? Instead of building complex software on top of an IDE, this project goes in the opposite direction: how does the simplest possible Arduino program work on a deeper level?