Tools

The hand-drawn-style whiteboard chalk's own boards are drawn in - every board on this site started as an .excalidraw file.

Paste code, see the actual assembly your compiler emits - across dozens of languages and compilers, live and shareable.

Build a regex against real test strings with live match highlighting and a plain-language breakdown of every token.

A JSFiddle for SQL - run and share queries against real Postgres, MySQL, or SQLite instances in the browser.

GCHQ's "Cyber Swiss Army Knife" - chain together encode/decode, hash, and compression operations by dragging them into a recipe.

Drop in one paper and get a visual graph of the papers it's most related to - a map of a field instead of a citation list.

Interactive, visual explanations of machine learning research. It stopped publishing new issues in 2021, but the archive is still some of the clearest ML writing anywhere.

Brown University's interactive visual introduction to probability and statistics - drag sliders instead of staring at formulas.

Colin Scott's interactive version of the classic table - L1 cache to a cross-continent round trip, scaled to human time so the gaps actually land.

A free introductory book on cryptography, born from a conference talk - the primitives and the classic ways people misuse them.