React 19.1 is out, new JavaScript runtime better than Node.js, Safari 18.4 brings new WebKit features, and more

Hello JavaScript Enthusiasts! Welcome to this week's edition of "This Week in JavaScript"! Today, we're covering React's powerful new debugging tools, a revolutionary JavaScript runtime, the legal battle for the JavaScript name, and Safari's most impressive update yet—plus exciting new tools you won't want to miss! React 19.1: Debug Smarter, Render Smoother React 19.1 is here with some powerful dev-focused additions and performance polish. Owner Stacks: A dev-only tool to trace which components rendered what. It gives you more visibility than Component Stacks and is super useful for debugging complex trees. Suspense Upgrades: Boundaries now play nicer across the client, server, and hydration stages—plus better GC handling and fewer unnecessary renders. React Server Components: A new experimental unstable_prerender API plus streaming support in edge environments. React DOM Fixes: Toggle events, better image preloading, and weird DOM edge cases got cleaned up too. React 19.1 isn’t flashy—but it’s smooth, powerful, and developer-first. Bare: A Minimalist Runtime for Max Flexibility Think Node.js, but leaner. Bare is a new JavaScript runtime built on V8 and libuv, but without a standard library. You assemble your own runtime from modular userland packages. Highlights: Full ESM + CommonJS support Native addon and multithreaded mobile support Works with multiple JS engines (V8, QuickJS, JavaScriptCore) Built for mobile, embedded, peer-to-peer, and experimental environments If you're tired of bloated runtimes or want complete control over your runtime stack, Bare might be what you’re looking for. Deno vs Oracle: The Battle for "JavaScript" Yes, Oracle still owns the trademark for “JavaScript.” And no, they haven’t built or maintained it in years. Here’s what’s happening: Deno filed a petition to cancel the trademark, arguing the term is now generic and that Oracle hasn’t used it in commerce. Oracle responded... by submitting a Node.js screenshot (which they don’t own) as proof of use. The next few weeks are key. If the fraud claim is allowed, Oracle may have to explain that submission. The outcome could impact how we use the word “JavaScript” publicly—whether in conferences, products, or dev tools. Deno’s pushing to #FreeJavaScript, and the industry is watching closely. Safari 18.4: WebKit Gets Wild This might be Safari’s most packed update ever. Here’s the highlight: Declarative Web Push: Notifications without Service Workers. It’s simpler, faster, and more battery-friendly. Iterator Helpers: map, filter, some, reduce, and more are now native in JS. Faster JSON Parsing: Thanks to SIMD, JSON.parse and stringify just got snappier. Error.isError: Better native error detection. CSS Goodies: shape(), text-autospace, sideways writing modes, scroll-linked animations for , and responsive design tools. Media & Web APIs: WebM, Opus, AV1, WASM JIT fallback, and CHIPS for cookie partitioning. Also, Web Extensions get a massive update, and WebKit's dev tools just got a lot more capable across iOS, macOS, and visionOS. Tools & Releases You Should Know About Let's speed-run through some of the other big tool updates this week! Express v5.1: JavaScript's classic server framework is back as the default on npm after years of modernization. It brings a migration codemod from v4, updated docs, a clear LTS strategy, and support for Uint8Array in res.send(). This is Express's biggest refresh in over a decade. React Email 4.0: Your email's new personal assistant with a built-in linter for links and images, SpamAssassin-powered spam scoring, and compatibility checking across email clients. With responsive previews and eight new components, building marketing-ready emails with React just got dramatically easier. zx 8.5: Now fully modular with a lightweight @lite version that's 7x smaller. Available everywhere—npm, GitHub, Docker, and JSR—with support for fetch().pipe(), enhanced globbing, better CLI flags, and cleaner stack traces. Perfect for scripting across Deno, Docker, or Node environments. Anime.js 4.0: Transform your browser into a motion design playground with this all-in-one animation engine. Now supports scroll observers, shape morphing, draggable elements, and timeline orchestration through a clean API. Perfect for animating anything from DOM elements to SVGs with buttery smooth performance. TinyBase 6.0: Future-proofs your stack by going fully ESM-only and dropping CommonJS and UMD. Adds support for React 19, modernizes testing, and updates demos to use import maps and esm.sh. The CLI is gone, but the core is leaner and more aligned with where frontend development is heading. And that's it for the twenty-ninth issue of "This Week in JavaScript", brought to you by jam.dev—the tool that makes it impossible for your team to send you bad bug reports. Feel free to share this newsletter with a fellow developer, and make sure you're

Apr 6, 2025 - 18:06

React 19.1 is out, new JavaScript runtime better than Node.js, Safari 18.4 brings new WebKit features, and more

Hello JavaScript Enthusiasts!

Welcome to this week's edition of "This Week in JavaScript"!

Today, we're covering React's powerful new debugging tools, a revolutionary JavaScript runtime, the legal battle for the JavaScript name, and Safari's most impressive update yet—plus exciting new tools you won't want to miss!

React 19.1: Debug Smarter, Render Smoother

React 19.1 is here with some powerful dev-focused additions and performance polish.

Owner Stacks: A dev-only tool to trace which components rendered what. It gives you more visibility than Component Stacks and is super useful for debugging complex trees.
Suspense Upgrades: Boundaries now play nicer across the client, server, and hydration stages—plus better GC handling and fewer unnecessary renders.
React Server Components: A new experimental unstable_prerender API plus streaming support in edge environments.
React DOM Fixes: Toggle events, better image preloading, and weird DOM edge cases got cleaned up too.

React 19.1 isn’t flashy—but it’s smooth, powerful, and developer-first.

Bare: A Minimalist Runtime for Max Flexibility

Think Node.js, but leaner. Bare is a new JavaScript runtime built on V8 and libuv, but without a standard library. You assemble your own runtime from modular userland packages.

Highlights:

Full ESM + CommonJS support

Native addon and multithreaded mobile support

Works with multiple JS engines (V8, QuickJS, JavaScriptCore)

Built for mobile, embedded, peer-to-peer, and experimental environments

If you're tired of bloated runtimes or want complete control over your runtime stack, Bare might be what you’re looking for.

Deno vs Oracle: The Battle for "JavaScript"

Yes, Oracle still owns the trademark for “JavaScript.” And no, they haven’t built or maintained it in years.

Here’s what’s happening:

Deno filed a petition to cancel the trademark, arguing the term is now generic and that Oracle hasn’t used it in commerce.
Oracle responded... by submitting a Node.js screenshot (which they don’t own) as proof of use.
The next few weeks are key. If the fraud claim is allowed, Oracle may have to explain that submission.

The outcome could impact how we use the word “JavaScript” publicly—whether in conferences, products, or dev tools. Deno’s pushing to #FreeJavaScript, and the industry is watching closely.

Safari 18.4: WebKit Gets Wild

This might be Safari’s most packed update ever. Here’s the highlight:

Declarative Web Push: Notifications without Service Workers. It’s simpler, faster, and more battery-friendly.
Iterator Helpers: map, filter, some, reduce, and more are now native in JS.
Faster JSON Parsing: Thanks to SIMD, JSON.parse and stringify just got snappier.
Error.isError: Better native error detection.
CSS Goodies: shape(), text-autospace, sideways writing modes, scroll-linked animations for , and responsive design tools.
Media & Web APIs: WebM, Opus, AV1, WASM JIT fallback, and CHIPS for cookie partitioning.
Also, Web Extensions get a massive update, and WebKit's dev tools just got a lot more capable across iOS, macOS, and visionOS.

Tools & Releases You Should Know About

Let's speed-run through some of the other big tool updates this week!

Express v5.1: JavaScript's classic server framework is back as the default on npm after years of modernization. It brings a migration codemod from v4, updated docs, a clear LTS strategy, and support for Uint8Array in res.send(). This is Express's biggest refresh in over a decade.
React Email 4.0: Your email's new personal assistant with a built-in linter for links and images, SpamAssassin-powered spam scoring, and compatibility checking across email clients. With responsive previews and eight new components, building marketing-ready emails with React just got dramatically easier.
zx 8.5: Now fully modular with a lightweight @lite version that's 7x smaller. Available everywhere—npm, GitHub, Docker, and JSR—with support for fetch().pipe(), enhanced globbing, better CLI flags, and cleaner stack traces. Perfect for scripting across Deno, Docker, or Node environments.
Anime.js 4.0: Transform your browser into a motion design playground with this all-in-one animation engine. Now supports scroll observers, shape morphing, draggable elements, and timeline orchestration through a clean API. Perfect for animating anything from DOM elements to SVGs with buttery smooth performance.
TinyBase 6.0: Future-proofs your stack by going fully ESM-only and dropping CommonJS and UMD. Adds support for React 19, modernizes testing, and updates demos to use import maps and esm.sh. The CLI is gone, but the core is leaner and more aligned with where frontend development is heading.

And that's it for the twenty-ninth issue of "This Week in JavaScript", brought to you by jam.dev—the tool that makes it impossible for your team to send you bad bug reports.

Feel free to share this newsletter with a fellow developer, and make sure you're following for more weekly updates.

Until next time, happy coding!