Cute example of configuring Emacs to avoid GC when the minibuffer is open (so completion is quick):
miniblog.
Related Posts
A cute systemd feature to get the system clock roughly correct: if the system time is before the compilation time of the systemd binary, it moves the clock forward to that time!
One cute feature of markdown I'd not noticed before: there's no syntax for images *without* a description (i.e. alt text).
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