Typed superset of JavaScript from Microsoft that has been production-usable for years before the panel. Panelists strongly recommend it (and Flow) for making projects maintainable at scale, easing refactoring, and catching bugs before runtime via type checks — saving time even before the code runs. Microsoft invests heavily in integrating TypeScript with the current JavaScript ecosystem out of the box and is promoting it aggressively (potentially at the expense of .NET, in favor of TypeScript + PWA). One panelist actively encourages attendees at local Ember meetups to adopt TypeScript.