TypeScript was developed by Microsoft and released in 2012. Microsoft made the language public on October 1, 2012, with the release of version 0.8, after roughly two years of internal development. It was designed to make large JavaScript projects easier to build and maintain by adding optional static typing and other development features.
TypeScript is a superset of JavaScript, meaning ordinary JavaScript code can generally be used inside a TypeScript project. TypeScript source is transpiled into JavaScript, allowing it to run in browsers, Node.js, and other JavaScript environments. Its type annotations, interfaces, generics, and compile-time checking help developers find many errors before a program runs.
Anders Hejlsberg, known as the chief architect of C#, was a major designer of TypeScript, alongside Microsoft engineers including Luke Hoban. The language reached version 1.0 at Microsoft's Build conference in 2014. A frequent confusion is treating TypeScript as a replacement runtime for JavaScript; it is instead a development language that compiles to JavaScript.