Deno joins Cloudflare as runtime development winds down

Deno joins Cloudflare with Ryan Dahl and the entire Deno team shifting their future development work to Cloudflare’s Workers and Durable Objects platform. The move redirects a separate JavaScript runtime and hosting effort toward making the Workers programming model easier to operate on developers’ own infrastructure, while setting transition dates for Deno users.

Deno said on October 9 that it will maintain the open-source Deno runtime for another year through monthly releases containing bug fixes and security updates. After that period, the current team will stop developing the runtime. The code will remain open source, and Deno said it welcomes other maintainers that want to continue the project.

The announcement is a material change for users of Deno’s hosted products. Deno Deploy is scheduled to remain online for six months before shutting down. Deno said paying Deploy customers moving to Cloudflare Workers will receive migration support. JSR, the JavaScript registry, will continue operating, with its infrastructure moving to Cloudflare.

What will Deno and Cloudflare build together?

The technical focus is a merger of celld, a project Dahl started, with Cloudflare’s open-source workerd runtime. Dahl said the aim is to make it easier to build and operate distributed applications using the Workers and Durable Objects programming model outside Cloudflare’s own network.

Durable Objects are individually addressable, single-threaded components with persistent storage. Dahl described them as a way to distribute an application across machines while the platform handles placement, routing and durable storage. In Cloudflare’s description, each object can include a relational database and support WebSockets, making the model relevant to real-time applications as well as stateful services.

Workerd is already open source, but Dahl said its Durable Objects support has been limited to a single instance. Celld was intended to provide a distributed version, designed as one Rust binary with object storage as its external service dependency. The combined work is intended to extend that model to self-hosted deployments.

Dahl framed the change as a response to limits he encountered with Deno and Deno Deploy. Deno improved parts of the JavaScript development experience, he wrote, but did not change the wider infrastructure work involved in distributing computation, coordinating state, managing storage and scaling networked applications. The new team’s work will concentrate on those problems through Workers and Durable Objects rather than continued development of a standalone Deno runtime and hosting service.

• Deno runtime: monthly bug-fix and security releases for one year, then development by the current team ends.
• Deno Deploy: scheduled to operate for six months, followed by shutdown and migration support for paying customers moving to Workers.
• JSR: continues operating, with infrastructure moving to Cloudflare.
• Engineering work: celld and workerd are to be brought together around self-hosted Workers and distributed Durable Objects.

This story draws on original reporting from The Register.