The Journey of Anders Hejlsberg: From Turbo Pascal to TypeScript

In 1996, a 36‑year‑old Anders sits in his office reflecting on his career.

Born in 1960 in Copenhagen, Anders first learned programming with ALGOL in high school, quickly mastering it and helping his teacher.

He opened Copenhagen’s first computer shop, wrote many programs in BASIC before moving to assembly, creating a 12 KB ROM‑based compiler that later became Poly Pascal for CP/M and DOS.

Partnering with Philippe Kahn, they added an editor to form the legendary Turbo Pascal IDE, which ran in just 33 KB and achieved massive commercial success, making Anders a millionaire.

After PolyData’s financial troubles, Anders joined Borland as chief architect, continuing Turbo Pascal development, but the rise of C/C++ and Windows caused its decline.

Seeing the success of Visual Basic, Anders led a team to revamp Turbo Pascal, resulting in Delphi 1.0 in 1995, which sold over 500 000 copies worldwide.

Internal disagreements at Borland eventually marginalized Anders, prompting his move to Microsoft in 1996, where he contributed to Visual J++ and later created the C# language for the .NET platform.

Recognizing the limitations of JavaScript for large‑scale IDEs, Anders helped design TypeScript, a superset of JavaScript that compiles to plain JavaScript, continuing his legacy of improving programming tools.

From Turbo Pascal to Delphi, C#, and TypeScript, Anders’ work has shaped four generations of programmers and remains a cornerstone of software development history.