Deno creator Ryan Dahl joins Cloudflare; Deno runtime to wind down over the next year

What happened

Ryan Dahl announced last week that the Deno team is joining Cloudflare, according to a retrospective published by vlt, the company behind the vlt package manager. Under the arrangement, the Deno runtime winds down over the coming year, the JSR registry keeps running on Cloudflare's infrastructure, and — per Cloudflare's own announcement — the team's new job is merging Deno's celld component into workerd, the engine that powers Cloudflare Workers.

The news landed two years to the day after Deno 2 shipped, and roughly ten months after Bun, the other prominent venture-backed alternative runtime, was absorbed by Anthropic. The obvious takeaway is that the experiment with alternative runtimes has ended, with Node left standing as the default. vlt's counterargument: the ecosystem absorbed most of what Deno was pushing for anyway, just not from Deno itself.

From clean break to Node compatibility

Deno began at JSConf EU in 2018 as an explicit critique of Node. As vlt recounts, Dahl's original list included permissions denied by default, first-class TypeScript, web-standard APIs on the server, ES modules only and a single executable — and, notably, no npm, no package.json and no node_modules, with dependencies referenced directly by URL.

That last part eroded over time. Deno 1.0 shipped in 2020 on the original terms, then adopted the deps.ts convention (effectively a manifest), lock.json (a lockfile of integrity hashes) and import maps to bring back bare specifiers. Deno's documentation now recommends registries over raw HTTPS imports, citing version drift and reliance on the serving host — the very objections skeptics raised in 2018, now restated as official guidance. Among those skeptics, Node TSC member Matteo Collina warned in 2020 that a left-pad-style incident could recur with no central body able to repair it.

Bun accelerated the retreat. Bun 0.1 arrived in July 2022 with the opposite bet: a rebuilt toolchain chasing speed, but existing npm packages, package.json and drop-in Node compatibility. About six weeks later, per vlt, Deno announced npm: specifiers and a commitment to make the large majority of npm packages work within three months, alongside a new speed ambition. Deno 2, in October 2024, completed the turn with full Node and npm support — four years after launching as the escape from Node's ecosystem.

Pressure flowed back into Node

Deno never gained real traction in production, vlt writes; Node was as dominant in 2026 as in 2018. But the rivalry reshaped the incumbent. Since 2018, Node has shipped a global fetch, WebSocket, Web Streams and Web Crypto, a stable test runner with --watch, --env-file, single-executable builds, a stable permission model, type stripping on by default, node:sqlite and require(esm). vlt credits Node's largely volunteer contributors while arguing the timeline only holds because rival runtimes shipped these ideas first. In its telling, established projects are rarely short of ideas; what they lack is urgency, and rivals create it.

The same dynamic runs through the toolchain. WinterCG formed in 2022 to define a minimum common runtime API and continues as Ecma TC55. Yarn forced deterministic installs and lockfiles, pnpm proved node_modules could be small, and Bun forced performance work on the incumbents. pnpm and Bun also stopped running package install scripts by default years before GitHub, following a run of supply-chain worms, announced that npm 12 would do the same.

What survives the wind-down

JSR outlives the runtime, vlt suggests, because it is cheap to run, its API is documented and Cloudflare had a reason to keep it alive. The celld-into-workerd effort is framed as a meaningful new option: a self-hostable, open implementation of Workers and Durable Objects, led by Dahl and Bert Belder. Whether a community fork of Deno emerges, vlt adds, will test whether anyone values a runtime that is secure by default and built on web standards enough to fund one that is not attached to a cloud.

Why it matters

The two most popular independent JavaScript runtimes now sit inside companies whose core business is something else — Anthropic and Cloudflare — and Cloudflare has made clear that workerd's roadmap is its own. The broader lesson vlt draws is about how open ecosystems evolve: nobody had to leave Node to get fetch, a permission model or TypeScript without a build step, because competitors shipped those features first and the incumbent had to answer. Competing projects often lose even as their ideas win — and today's JavaScript ecosystem runs on a fair number of Deno's ideas.