Floating‑point math is everywhere: graphics, scientific computing, machine learning, and even everyday apps. Yet most developers and readers rarely stop to think about the tiny rounding errors that can silently change results. One compact, precise way to measure those errors is ULP — Units in the Last Place. This post explains what ULP means, why it matters, and how to reason with it.
Finding an old ULP.txt today is like finding a time capsule. It contains the digital signatures of the teenagers who grew up to build the modern internet. It captures the early spirit of open-source collaboration before it was even called that. ULP.txt