How Anders Hejlsberg Shaped Modern Programming: From Turbo Pascal to TypeScript

Anders Hejlsberg: A Brief Biography

Anders Hejlsberg, born on December 2, 1960 in Denmark, is a celebrated software engineer who authored Turbo Pascal, led the development of Delphi, and later designed C# and TypeScript at Microsoft.

Early Work and Turbo Pascal

While studying electrical engineering at the Technical University of Denmark, Hejlsberg wrote a Pascal compiler for the NASCOM microcomputer, which later evolved into PolyPascal and was acquired by Borland. Integrated into Borland's IDE, it became Turbo Pascal, widely regarded as one of the first true integrated development environments.

Delphi and the Rise of Object Pascal

At Borland, Hejlsberg created Delphi, an IDE built around Object Pascal. Delphi combined a powerful object‑oriented language with a visual component library (VCL) and runtime library (RTL), enabling rapid Windows application development. It became a cornerstone for many Chinese developers, including the creators of Foxmail, CCED, and WPS.

Joining Microsoft and Shaping .NET

Impressed by Delphi's success, Microsoft pursued Hejlsberg aggressively. After several offers, Bill Gates personally promised Hejlsberg the freedom to pursue his technical interests, leading to a move to Microsoft in 1996. There he became the architect of Visual J++, the precursor to Visual J++, and later helped launch the .NET platform.

As one of the originators of .NET, Hejlsberg defined its vision as a platform for agile, rapid, and network‑transparent software development. To realize this vision, he designed a new language—C#—that combined the safety of Java with the performance of native code, while supporting full reflection and single inheritance with multiple interfaces.

TypeScript and Open‑Source Advocacy

In 2012 Hejlsberg introduced TypeScript, a superset of JavaScript that compiles to clean JavaScript for both client‑side and Node.js server‑side development. TypeScript dramatically improves developer productivity and reduces errors, and it marked Microsoft's early move toward open‑source software.

Legacy and Ongoing Contributions

Even in his sixties, Hejlsberg continues to write code and contribute to open‑source projects on GitHub. His work has earned him the Dobb Outstanding Programming Award and cemented his reputation as a visionary who consistently pushes the boundaries of programming language and tool design.