Elm is a language with immutable types (like Typescript) that is purely functional (like Haskell) and is a response to the cryptic error messages and hard to test edge cases of vanilla JS. In production it is often more performant than React, Angular, or Vue. If you like Elm, it can deploy incrementally, replacing just a single line of your existing code. This talk is for web developers who would like an introduction to Elm. Bring your computer: after giving examples that answer "Why Elm?" we will re-factor a static HTML design into an Elm-compiled page with interactivity. If you have Node.js and NPM already installed, Elm installs in about a minute.