Terminad is a really interesting approach to rendering markdown in the CLI. It deliberately doesn't render links, so you can always see both the link text and the URL.
In a browser you have hover to see URLs, but not necessarily in a terminal.
Today I learnt about clippy::clone_on_ref_ptr, which complains about t.clone() on a Rc<Thing>. You write Rc::clone(t) instead, so it's obvious it's a cheap clone.
It's a nice approach, because it makes the expensive clones more obvious.
Really cute approach to reporting type errors: when there's a type error, show an example of a runtime error that the type check has prevented!
Data-Driven Techniques for Type Error Diagnosis https://escholarship.org/uc/item/59s4h4pv