Slashdot has reported:

Cloudflare has acquired Deno, the company behind the server-side JavaScript and TypeScript runtime created by Ryan Dahl, the inventor of Node.js. Dahl and 12 Deno colleagues will join efforts to expand Cloudflare’s Workers platform for potential open-source use, centred on celld, a system intended to let developers run Workers applications on their own infrastructure as well as Cloudflare’s network.

The acquisition shifts the team’s focus toward a self-hosting platform for distributed applications. Cloudflare will maintain the Deno runtime with bug fixes and security patches for the next year, while the Deno project remains open source and its developers welcome others to continue its development. Deno Deploy will keep operating for six months before shutting down, and paying customers will receive migration support to move to Cloudflare Workers.

Deno’s JSR package registry for JavaScript and TypeScript will continue operating, with its infrastructure moving to Cloudflare. The company’s announcement presents the change as a decision about where to focus engineering work after building Deno Deploy, its application platform. Dahl said the experience exposed additional complexity below the developer-facing service.

“We wanted to make running applications as straightforward as possible,” Dahl wrote on the official Deno blog. “But building and operating Deploy also showed us how much complexity remained underneath that developer experience. I wanted to simplify that layer, too.”

That work led to celld, which builds on the Cloudflare Workers programming model. The project is designed to let developers create distributed applications from the outset while keeping operations straightforward. Dahl said he wants scaling to be part of the programming model instead of infrastructure that each application must assemble, and said the goal is to make the model a standard way to build servers, whether they run on Cloudflare or on a customer’s own infrastructure.

In an account on the Cloudflare blog, Dahl said the team’s work on Deno improved the experience of writing JavaScript but did not change what developers had to assemble around the runtime. He identified larger challenges in networked applications, including distributing computation, coordinating state, storing data and scaling to meet demand.

Dahl said the idea for a different approach came from Cloudflare Durable Objects. He described them as a powerful abstraction: a distributed singleton paired with a SQLite database. Each object acts like a small, individually addressable server with its own relational database. Its JavaScript runs on a single thread, which Dahl said is easy to reason about; it can handle WebSockets, and its local SQLite database can be accessed synchronously.

Dahl used a chat service as an example. Assigning one Durable Object to each channel shards the data and WebSocket connections, helping an application scale. He said the model gives developers compute, relational databases, queues and real-time communication primitives designed for applications distributed across machines. He is especially interested in the potential for AI agent harnesses, which can use inexpensive serverless execution, persistent state, WebSockets and a high-level JavaScript interface.

“ The need for better abstractions is especially acute with AI. Durable Objects bring together capabilities that are particularly useful for agent harnesses: inexpensive, serverless execution, persistent state, WebSockets, and a high-level JavaScript interface. This is what I'm most excited to explore and why celld focuses on Durable Objects,” Dahl wrote on the Deno blog.

Celld was released in August as a single Rust binary that runs Workers and Durable Objects across multiple machines. Object storage is its only external dependency. Operators run multiple celld instances against one storage bucket, while the software manages placement, routing and persistence. Dahl and Deno co-founder and colleague Belder will lead work to merge celld into workerd and make self-hosting a supported way to run Workers applications. The stated result is that customers could build an application on Cloudflare’s network and transfer it to a private data centre without rewriting it.

The acquisition also addresses criticism that applications built for Cloudflare Workers cannot easily be moved elsewhere. Forbes argued that the deal turns that long-standing objection into a selling point, offering customers a concrete portability option as they assess serverless and edge platforms. The source account also suggests that celld could mark another major shift in server-side JavaScript, with a runtime requiring only 300 KB of memory per instance rather than the hundreds of megabytes used by Node or Deno. Those savings could matter to a cloud provider, particularly one serving the growing agentic market.

Deno began in 2018 as Dahl’s attempt to rewrite Node and address what he considered mistakes in the earlier project. Its name is an anagram of Node, and its design included built-in fetch, a permission model and native TypeScript support. Sequoia backed Dahl’s company with $21 million in 2022, and Deno had 400,000 monthly users as of August. Despite that growth, Node’s established position made it difficult for Deno to gain broader adoption.

“What we found over years of working on Deno is that you can't really deviate from Node.js very much,” Dahl told The Register. “As we continued to try to get adoption for Deno, we found we had to essentially backpedal on some of the original promises and become more Node compatible over time, and that left us as a kind of an alternative Node.js implementation.” The Register reported that Cloudflare would maintain the runtime for another year before ending its development, a timeline that aligns with the promised period of bug fixes and security patches.

Dahl said, “I am now of the opinion that if you're choosing Node.js for building servers, you're doing it wrong.” He also argued that conventional servers operate at the Linux virtual machine layer, unlike Cloudflare Workers. With the acquisition, the team’s work will centre on that Workers model and on making it possible to run applications beyond Cloudflare’s network.