JavaScript has often been described as the “assembly language of the Web.” Implied in this description is the notion that other languages can and should compile into JavaScript. We have seen examples of this, most prominently with ClojureScript. But Scala, a popular programming language that runs on the JVM, now has a version that compiles into JavaScript, as well: Scala.js. This talk, by Scala.js author Sébastien Doeraene, describes the aims of the project, how well Scala.js programs can interact with other JavaScript libraries and functionality, and what Scala’s typing does to improve the state of JavaScript programming.