Deno gets a final year, TanStack Start reaches 1.0, and JPEG XL meets AVIF

The Deno team is folding into Cloudflare and the runtime has a year left, TanStack Start went stable, and a week after Chrome shipped JPEG XL, Jake Archibald put it up against AVIF. The Interop 2027 rankings kept coming, and scroll-triggered animations got a guide and a debugger. This page also catches up on nine posts from last week that reached us late. 75 posts from 45 sources.

Deno's last year

The details came out this week. The Deno team isn't joining Cloudflare to keep working on Deno, but to fold celld into workerd so Durable Objects can be self-hosted. The runtime gets a final year of fixes, Deno Deploy closes in six months and JSR moves to Cloudflare's infrastructure. On Hacker News, Ryan Dahl said Deno "has been sucked into the gravity well of Node compatibility" and asked, "Why reimplement Node? It works." (JavaScript Weekly).

• Bytes wrote a eulogy for Deno, crediting it with the ideas others adopted: scoped permissions (which informed Node's permission model), browser-standard APIs on the server with WinterCG, and running TypeScript without a build step.
• David Bushell, who had already said goodbye to Deno, doubts a community fork will last, and looks back on everything he wrote about it since 2021.
• Maximilian Schwarzmüller says Cloudflare bought Deno for the team, the runtime and celld, not for Deno itself, and Syntax Weekly asks whether Deno is really dead, along with OpenCode 2 and the Bootstrap 6 alpha.

Node, Bun and the rest of JavaScript

• Bun 1.4.3 adds bun check, a port of TypeScript 7's type checker that reports the same errors as tsc. Jarred Sumner says it runs 3–6x faster (JavaScript Weekly).
• AWS Lambda Web Functions run an ordinary Express, Hono or Fastify server on Lambda without rewriting it around an event handler.
• Node 26.12.0 makes configuration files stable, and Node 24.22.0 LTS gets util.throttle and util.debounce. Security releases for 26.x, 24.x and 22.x are due on 21 October, Node 26 becomes the active LTS line on 28 October, and the NodeConf EU 2026 talks are on YouTube (Node Weekly).
• The 2026 Stack Overflow survey had 30,903 respondents and JavaScript is the top language for the 12th year in a row. And despite the noise, no malicious Zod release reached npm: bad commits pushed in September were reverted the same day.

Frameworks

TanStack Start 1.0 is stable, for React and Solid. This Week In React describes it as client-first, with SPA-style routing, server rendering and typed server functions, and its packages ship skills so coding agents can learn its APIs. Bytes calls it Next.js's biggest competition, and credits simpler primitives, end-to-end types and not being tied to one host. Lovable already makes it the default for all its apps.

• Expo will maintain React Native Web under the React Foundation, Tamagui v3 and One v2 are out, and React Native 0.88 is at RC5 (This Week In React).
• Master.dev has tips for TanStack Start with Durable Objects, and the first part of an intro to TanStack AI: setup, streaming, persistence and resumability.

JPEG XL vs AVIF

Chrome 155 decodes JPEG XL with jxl-rs, a pure Rust decoder, because image decoders are one of a browser's most attacked surfaces. The Chrome team suggests trying both formats, and expects JPEG XL to help most with high-fidelity or lossless images.

Now that JPEG XL is in all major browsers, Jake Archibald compared the two, and AVIF wins almost everywhere:

• Lossy photos: the best JPEG XL file is usually 15–25% larger than the AVIF at default effort, 6–20% at maximum effort. There are outliers, so it's worth trying both for one important image.
• Screenshots and illustrations: JPEG XL is 30–90% larger at default effort, and lossy AVIF handles them fine.
• Transparency: AVIF is much better.
• Decoding: JPEG XL typically takes 2–3x as long at medium quality.
• The encoder matters: the newer jixel usually beats libjxl, except on detailed transparency.

Browsers and Interop 2027

Eric Meyer ranks Temporal first for Interop 2027, as a personal list that won't decide how he votes for Igalia. Sara Soueidan's top picks are the focusgroup attribute, ariaNotify(), the headingoffset and headingreset attributes with :heading(), and interest invokers. Firefox's ranking tool is back for a second year, and Frontend Focus quotes Jake Archibald saying last year's ~1,900 rankings helped "prioritise a lot of work this year".

• Chromium has had a <geolocation> element since 154. Like the camera and microphone elements, it lets users grant permission again by clicking it, with watch, accuracymode and autolocate attributes (Modern Web Weekly).
• LogRocket gave the AI debugging MCPs from Chrome, Safari 27 and Firefox a React app with four planted bugs. All three found them, but only Firefox got the React bug exactly right, by opening the source file. Chrome and Safari blamed a missing memo that was already there. The author calls it a field report, from one or two runs each.
• Also in Frontend Focus: from February, new Let's Encrypt certificates last 64 days by default, Firefox has an Enterprise edition, and Darius Cepulis tried the Device Posture and Viewport Segments APIs in the iPhone Duo simulator.
• WebKit fixed CSS selector invalidation when an element moves and added moving steps for <optgroup> and <hr> (Igalia).
• Zach Leatherman made a Firefox add-on for his 300+ tabs: find duplicates, sort by last use, and save tabs to restore later.

CSS

Scroll-triggered animations got a long guide and a debugger. Utilitybend explains why scroll-driven isn't enough: a card fading in shouldn't follow the scroll speed; it should play a normal animation once it enters, the job IntersectionObserver used to do. Bramus released a DevTools extension that draws a trigger's activation and active ranges on a minimap and lets you edit them live.

• Ahmad Shadeed uses calc-size() with round() so a section's height is always a multiple of its background tile, with no cut-off at the bottom. Chrome only for now.
• Master.dev builds a scrollspy without JavaScript, and Patrick Brosset a dashboard with Grid Lanes where align-self: stretch avoids a jagged bottom edge.
• Bramus also built css-typed-om, a polyfill tested against Web Platform Tests, since Firefox's Typed OM is still behind a flag.
• Anthony Frehner found that a lazily loaded @property restyles every element in the document, because registration is global, and proposes non-global @property.
• Kevin Powell asks whether we really need alpha(), and explains why he still teaches CSS: one-shot prompting is making sites look the same, like the Bootstrap years.

Icons without inline SVG

Two posts take on icon markup. Lea Verou builds a pure CSS icon system from --icon custom properties, @property, style queries and mask, without touching the HTML. Master.dev covers Vadim Makeev's SVG linked parameters: a fill like env(--color, #c1f07c) inside an SVG loaded with <img> can be styled from the page, and browsers without support use the fallback.

HTML, accessibility and publishing

• TetraLogical's Accessible Components Library has documentation, accessibility requirements and test scenarios for each component (The Index #202).
• EPUB 3.4 adds a roll layout for vertically scrolling webtoons, along with EPUB Accessibility 1.2. Existing books stay valid.
• CodePen's v2 API gives full read and write access to your Pens, Collections and Assets, over GraphQL or REST.

Catching up from last week

These were published between 5 and 11 October, but reached us after last week's page was written.

• Chrome's WebGPU update for 155–156 adds a WGSL fragment_depth extension: say whether a shader's written depth is less or greater than the interpolated one, and the GPU can keep early-Z optimizations on.
• Chrome's Email Verification origin trial now works on Android and supports third-party trials, and Chrome is preparing to ship it.
• Adam Argyle and Robbie talk token limits and parallel agents, and why the meta-harness layer is probably going to die soon.

Lea Verou's icons, Sara Soueidan's Interop picks, Anthony Frehner's @property proposal and Chrome's JPEG XL post are in the sections above.

AI, agents and the mood

Theo says Anthropic went from 2,500 merges a day to over 30,000 in September with a system called Scion. He also tested Meta's Muse Wonder Full, which he says makes Meta a frontier lab, and Google's Gemini 4 Argon, and explains why AI is getting cheaper but not on your bill yet.

• Syntax covers Pi's updates: durable long-running agents, Codemode and MCP support. They also ask whether pull requests are dead and note Supabase picking up Turso. Moving an agent to Pi Durable, which saves its place so a crash doesn't lose work, let one of them delete about 8,000 lines of custom code.
• Someone clean-room ported seven Adobe apps to Rust with AI help. Syntax is impressed by how good it is, but says inventing what comes next is the hard part, and midudev asks whether it's the beginning of the end for Adobe (in Spanish).
• Front-End Fire says AI-generated submissions are swamping maintainers and bug bounties, so open source is closing its gates.
• Stefan Judis in Web Weekly #201: "AI makes projects with weak engineering culture fail much faster." Smashing Magazine sees organizations repeating the mistakes of digital transformation: buying licences and treating AI as technology instead of a change in how people work.
• Yoav Weiss's case that "WebMCP is Agentic WebPerf": a site that exposes its actions as tools saves agents from working it out from scratch every time.
• TJ Pitre joins Shop Talk on design systems built with AI: keeping Figma and code in sync, human review and evals.
• midudev on three safety researchers fired from OpenAI, and the death of Margaret Hamilton, a key figure behind the Apollo 11 software (both in Spanish).