As TypeScript turns 10 in December, its co-creator talks about getting Microsoft to embrace open source and how it became a go-to language for building web apps
Context & Ripple Effects
The anniversary interview lands at the end of an arc that started well before open source was fashionable at Redmond: in 2015, Microsoft partnered with Google on Angular 2, wiring TypeScript into a rival's flagship web framework, and the same season saw Azure CTO Mark Russinovich calling an open source Windows "definitely possible". What began as an internal argument about releasing compiler source became a developer-credibility campaign that culminated in Microsoft buying GitHub — per Bloomberg's reporting, the platform had 36M registered developers at the time.
First-order effects
- The co-creator's account formalizes TypeScript as the case study in Microsoft's open source pivot — a Microsoft-originated language now validated by GitHub data showing it passed both Python and JavaScript in August to become the most used language across 180M+ developers.
Second-order effects
- Microsoft's tooling and cloud businesses inherit the flywheel: a language that tops GitHub usage keeps the developer base that made the GitHub acquisition strategically coherent, while framework vendors like Google — already partnered since the Angular 2 work — treat TypeScript compatibility as table stakes rather than a differentiator.
Third-order effects
- The pattern suggests platform companies now compete for developers by giving away languages, runtimes, and hosting for code rather than locking them to an OS — the shift from Windows SDK-era control to ecosystem stewardship that TypeScript's adoption curve measures more cleanly than any announcement could.
The trend: Microsoft's decade-long conversion from closed platform vendor to open-source developer-platform operator is the larger story, and TypeScript crossing into the most-used language on GitHub is its clearest measurable payoff.