

Simultaneously, the source code, which was initially hosted on CodePlex, was moved to GitHub. Further improvement were made in July 2014, when the development team announced a new TypeScript compiler, asserted to have a five-fold performance increase. Visual Studio 2013 Update 2 provides built-in support for TypeScript. TypeScript 1.0 was released at Microsoft's Build developer conference in 2014. TypeScript 0.9, released in 2013, added support for generics. As of April 2021 there is support in other IDEs and text editors, including Emacs, Vim, WebStorm, Atom and Microsoft's own Visual Studio Code. Soon after the initial public release, Miguel de Icaza praised the language itself, but criticized the lack of mature IDE support apart from Microsoft Visual Studio, which was not available on Linux and OS X at that time. TypeScript was released to the public in October 2012, with version 0.8, after two years of internal development at Microsoft. Anders Hejlsberg, lead architect of C# and creator of Delphi and Turbo Pascal, has worked on the development of TypeScript. It is licensed under the Apache License 2.0. The TypeScript compiler is itself written in TypeScript and compiled to JavaScript. TypeScript headers for the Node.js library modules are also available, allowing development of Node.js programs within TypeScript. There are third-party header files for popular libraries such as jQuery, MongoDB, and D3.js.

This enables other programs to use the values defined in the files as if they were statically typed TypeScript entities. TypeScript supports definition files that can contain type information of existing JavaScript libraries, much like C++ header files can describe the structure of existing object files. The default TypeScript Compiler can be used, or the Babel compiler can be invoked to convert TypeScript to JavaScript. Multiple options are available for transpilation. TypeScript may be used to develop JavaScript applications for both client-side and server-side execution (as with Node.js or Deno). Because TypeScript is a superset of JavaScript, all JavaScript programs are syntactically valid TypeScript, but they can fail to type-check for safety reasons. It is designed for the development of large applications and transpiles to JavaScript.

TypeScript is a free and open-source high-level programming language developed by Microsoft that adds static typing with optional type annotations to JavaScript.
