Deno (and Node.js) inventor Ryan Dahl has posted that his team is joining Cloudflare and that after one more year of support “we will end our development of the Deno runtime. Deno will remain open source, and we welcome others who want to continue its development.”
Deno 1.0 was released in 2020 as an attempt to fix what Dahl called “design mistakes in Node”. Deno is built in Rust, supports TypeScript natively, takes advantage of V8 sandboxing, but at launch did not support Node modules, limiting compatibility.
Deno’s initial take-up was limited by lack of Node.js compatibility, a problem the project attempted to fix in Deno 2.0, released in October 2024. Retro-fitting Node.js compatibility must have been a big drain on resources, absorbing effort that could have gone into improving the runtime.
In the meantime, Node.js worked on adding native TypeScript support, delivered in early 2025 by Node.js 23.6 in experimental form.
Deno also suffered from the rise of Bun, another JavaScript runtime and bundler, first released in September 2023, with TypeScript support, some Node.js compatibility, and fast performance. Bun evolved rapidly and was acquired by Anthropic in December 2025. Bun continues to improve, with the latest 1.4.3 release adding a TypeScript type checker which is a port of Microsoft’s typescript-go (now just TypeScript 7) to Rust, with a claimed 3x performance improvement.
The Deno project’s business model depended on enterprise support contracts and hosting via Deno Deploy, perhaps not sufficient for the long-term health of the project.
Dahl writes that “we know this is a consequential change for people who have built on Deno,” but offers little comfort to users. Deno Deploy will be discontinued in 6 months. The JSR registry, designed as a superset of the npm registry and as TypeScript-first, will continue.
On Reddit Deno users debate where to go. Might Deno survive as an independent open source project (unlikely)? One says: “we are all back to Node these days” and another, “perhaps now is a good opportunity to consider .NET.”