WasmAssembly

Scala.js to Wasm—Exploring the Wasm backend for Scala.js with Sébastien Doeraene

The JVM-to-Web journey continues! In this episode, Thomas Steiner welcomes the original author of Scala.js, Sébastien Doeraene, to discuss the major, experimental leap to WebAssembly. You'll learn why the team decided to target Wasm now and how it complements the existing JavaScript emission. This episode offers a technical deep-dive into how Scala's powerful, nominal type system maps its objects and classes onto Wasm GC, and examines the critical details of interoperability, including what happens when a Scala object crosses the boundary to a JavaScript function. Finally, Sébastien covers the current status of the Wasm ecosystem for Scala.js, and the key limitations you need to know before you flip the `withExperimentalUseWebAssembly(true)` switch. Tune in to discover how a mature typed language is laying a fast, new foundation on the web!   Chapters: 0:00 -  Commonalities between composing music and composing compilers 1:38 - Scala, Scala.js, Scala Native, and the Scala Center 11:01 - The "elevator pitch" for Scala.js 14:59 - Is Scala.js competing with TypeScript? 20:31 - What motivated the decision to target Wasm? 26:40 - ] How Scala.js utilizes Wasm GC 31:24 - What's actually crossing the boundary between JS and Scala.js? 37:37 - BigInt support in Scala.js 38:38 - The status of the library ecosystem for the Wasm target 41:40 - Sébastien's hobby project ported to Scala.js 44:02 -  Is the Wasm backend purely a Scala.js thing for browsers? 52:38 - What developers should be aware of before flipping that `withExperimentalUseWebAssembly(true)` switch 58:28 -  What Wasm proposals are you waiting for to unlock new features in Scala.js? 59:57 - Wasm, but not    Resources:   Sébastien Doeraene on GitHub → https://goo.gle/4pMPufo  Sébastien Doeraene at EPFL → https://goo.gle/3KTZZhu   Ensemble vocal Évohé → https://goo.gle/4pApQu5  Scala → https://goo.gle/4iYZwY1  Scala.js → https://goo.gle/4oYze9E  Scala Native → https://goo.gle/4rX4hp0  Scala Center → https://goo.gle/44uffZ8  Scala to TypeScript → https://goo.gle/4j37ZcM  Tyrian → https://goo.gle/4iZCOik  Laminar: https://laminar.dev/   Scala.js WebAssembly backend → https://goo.gle/4oT4bvV  Announcing Scala.js 1.19.0 → https://goo.gle/4aSYM4F  Wasm GC proposal: https://github.com/WebAssembly/gc  JSPI proposal → https://goo.gle/4s5cIik  Scala.js Interoperability → https://goo.gle/4afJdE1  Scaladex homepage with stats → https://goo.gle/4ja7jCr  FunLabryrinhte (Scala) → https://goo.gle/4oTghoL   FunLabryrinhte (original) → https://goo.gle/3KA8EWx  Bringing Scala to Server-Side Wasm → https://goo.gle/4pgwC7v  Scala.js Wasm Limitations →  https://goo.gle/4s1jOnN  Custom descriptors proposal → https://goo.gle/4p8I7Og  Stack Switching Proposal → https://goo.gle/4pJG8B1  JS Primitives Builtins proposal → https://goo.gle/4akAnor  Shared-Everything Threads proposal → https://goo.gle/3MCCxGd  Watch more WasmAssembly → https://goo.gle/WasmAssembly  Subscribe to Chrome for Developers → https://goo.gle/ChromeDevs #WebAssembly #Wasm #ChromeForDevelopers #Chrome   Speaker: Thomas Steiner Products Mentioned: Web Assembly (Wasm),  Chrome,  WebAssembly for Chrome  

Kotlin/Wasm with Zalim Bashorov

Join WasmAssembly host Thomas Steiner for a deep dive into the world of Kotlin/Wasm with Zalim Bashorov from JetBrains! This episode of WasmAssembly explores how Kotlin, known for being concise, multiplatform, and fun, became the recommended language for Android, and why JetBrains decided to expand its reach to WebAssembly. They discuss how people are currently using Kotlin on the Web, the power of Kotlin Multiplatform, and the future of Kotlin/Wasm, covering exciting recent and new proposals like Garbage Collection, Exception Handling, and Shared-Everything Threads. Tune in to hear about the tooling, next milestones, and the evolving landscape of Kotlin development.   Chapters: 0:00 - Introducing Zalim from JetBrains 2:19 - Kotlin: Concise. Multiplatform. Fun. But what does this mean? 9:05 - How did Kotlin become the recommended programming language for Android? 16:17 - Why did JetBrains decide to support WebAssembly? 25:36 - People use Kotlin on the Web, but how? 31:15 -  What is Kotlin Multiplatform? 37:48 - Understanding canvas-rendered apps 41:17 - Could the HTML-in-Canvas proposal help? 43:59 - New Wasm proposals Zalim is excited about 54:29 - What about Kotlin on the server? Resources: Zalim Basharov on LinkedIn → https://goo.gle/4pis0y2  StackOverflow 2025 developer survey results → https://goo.gle/3WZuchN  Kotlin Programming Language → https://goo.gle/4ifxZkU  Google I/O 2019: Empowering developers to build the best experiences on Android + Play → https://goo.gle/3LLwpen  Kotlin Is Everywhere: https://goo.gle/4rlvdPc  Kotlin/Native → https://goo.gle/3LNk1KM  Kotlin/JavaScript → https://goo.gle/3XxkDH0  Kotlin/Wasm → https://goo.gle/4r53NwP  Kotlinx.browser → https://goo.gle/4o9WRvJ  Kotlin/Wasm browser template → https://goo.gle/49tzl9c  Get started with Kotlin/Wasm and Compose Multiplatform → https://goo.gle/3X8cmsW  Get started with Kotlin Multiplatform → https://goo.gle/48njI20  HTML-in-Canvas proposal → https://goo.gle/48sy8wX   Garbage collection proposal → https://goo.gle/4i4CgHw  Exception handling proposal → https://goo.gle/483coav  Shared-everything threads proposal → https://goo.gle/4474V9e  Stack switching proposal → https://goo.gle/49XiMCH  All ways to reach Zalim → https://goo.gle/3LG78lT   

WebAssembly from the Ground Up with Patrick Dubroy and Mariano Guerra

Get ready for WasmAssembly episode 16! Host Thomas Steiner sits down with Patrick Dubroy and Mariano Guerra, authors of the ebook "WebAssembly from the Ground Up." Discover how they're teaching Wasm by building a compiler in JavaScript, why writing WebAssembly by hand is crucial, and their thoughts on the future of compiler education. Tune in to learn about Ohm, the surprising omission of WAT, and what a potential part 2 of their book might cover! Chapters: 0:00 - Welcoming Patrick and Mariano, authors of "WebAssembly from the Ground Up 1:34 - How the book came to be 5:34 - How the co-authors met 9:13 - Who should learn WebAssembly by actually writing it? 13:13 -  Is it time to retire the Dragon Book? 17:42 - What is Ohm, what it has to do with the programming language Wafer, and why they chose Ohm for the book 27:22 - Compiling Ohm grammars to Wasm 30:22 - The on-purpose omission of the Wasm text format WAT 38:27 - A potential part 2 of the book 43:36 - The biggest surprise when writing the book 50:42 - Wasm, but not Resources: Mariano Guerra on LinkedIn: https://goo.gle/4gtIq3e  Patrick Dubroy on LinkedIn: https://goo.gle/46t7Ucx  WebAssembly from the Ground Up: https://goo.gle/3IvlqnT  Learn WebAssembly: https://goo.gle/46v50E0  WebAssembly website Issue: Consider adding a pure Wasm tutorial: https://goo.gle/46MlMzK  Let's Build a Compiler, by Jack Crenshaw: https://goo.gle/4gwQGzz  Simpletron Machine Language and Compiler from Deitel's Java book: https://goo.gle/4nK5CNf  Little Riak Core Book: https://goo.gle/48rMNtF   Failed PR "Initial tests for globals" to the Wasm spec:https://goo.gle/3IwfQ4I  Short lived "WebAssembly Weekly" newsletter: https://goo.gle/3IgQYOp  The Dragon Book: https://goo.gle/4pLnYPM  Ohm: https://goo.gle/3VWpu3B  Human Advancement Research Community (HARC):https://goo.gle/3Iqbf47  Communications Design Group (CDG):https://goo.gle/4px8zlK  Forth dialect implemented in C, JavaScript, WebAssembly and compiled from C to asm.js and WebAssembly: https://goo.gle/3KvZLfV  Minimal Object Oriented runtime in WAT and WasmGC:https://goo.gle/4nxxS5m  wasm-tools: https://goo.gle/4nyisxQ  Apple's Pascal "syntax" poster: https://goo.gle/4mvhX6X  Niklaus Wirth: https://goo.gle/424Bzax  Lilith Computer: https://goo.gle/4nECeru  Oberon System: https://goo.gle/4pvyP03  Bill Hader on feedback: https://goo.gle/3K9R76U  How Julia Evans asks for feedback: https://goo.gle/4gxwFZv  Patrick's blog post "Reflections on writing a book": https://goo.gle/4gx3Jkk  Quarterback: https://goo.gle/4gvIcc5  Max Bernstein's blog: https://goo.gle/46vlwUD  Thorsten Ball's newsletter: https://goo.gle/4pvoWzl  Gleam Programming Language: https://goo.gle/46H66hj  Sonic Pi: https://goo.gle/3I6z6Wv  Future of Coding Newsletter: https://goo.gle/3Isd4xi  Patrick Dubroy on Bluesky: https://goo.gle/3VZ6v8C   Patrick Dubroy on Mastodon: https://goo.gle/4pvzazR  Mariano Guerra on Bluesky: https://goo.gle/4pxInYa  Mariano Guerra on Mastodon: https://goo.gle/4n6OXn3  WebAssembly from the Ground Up ebook on Bluesky: https://goo.gle/4prbIUd  WebAssembly from the Ground Up ebook on Mastodon: https://goo.gle/4gxBwtX   

CG, WG, W3C, Lively—Wasm standardization with Thomas Lively - WasmAssembly

 In this episode of WasmAssembly, host Thomas Steiner welcomes Thomas Lively from Google, the new co-chair of the W3C WebAssembly Community Group. Taking over the role from past guest Deepti Gandluri (episode #2), we seize the opportunity to ask Lively the exact same three questions we posed to Deepti—listen back to compare their perspectives! In the second half, the two Thomases dive deep into the proposals Lively is personally championing, covering Custom Descriptors and JS Interop, and the highly-anticipated Shared-Everything Threads.   Chapters: 0:00 -  The Wasm team "Thomas" confusion 0:57 - Thomas' way into Google's Wasm team  4:10 - Wasm CG vs. Wasm WG  9:39 -  Is Wasm standardization moving slowly? 17:58 - Wasm at Google and the Chrome team  22:33 - The Custom Descriptors and JS Interop proposal  35:02 - The Shared-Everything Threads proposal  43:28 -  Wasm, but not Resources: Thomas Lively on LinkedIn → https://goo.gle/45U8uRA  WebAssembly Community Group → https://goo.gle/3K0qSj3  From asm.js to Wasm with Emscripten creator Alon Zakai → https://goo.gle/47zQTj9  CG, WG, W3C, Deepti—Wasm standardization with Deepti Gandluri → https://goo.gle/4ndWX5X  Custom Descriptors and JS Interop → https://goo.gle/4ggStbY   WebAssembly threads →​​ https://goo.gle/45Z0kaI  Shared-Everything Threads → https://goo.gle/47BnLYG  Thomas Lively on Bluesky → https://goo.gle/4gcm2v8   

Dart, Flutter, and WasmGC with Ömer Ağacan and Martin Kustermann

In this episode of WasmAssembly, your host Thomas Steiner is joined by Ömer Ağacan and Martin Kustermann from the Dart team at Google. They explore Dart, the language behind Flutter, and how Dart nearly landed in V8 alongside JavaScript, and why Flutter doubled down on Dart and WebAssembly Garbage Collection (WasmGC). Ömer and Martin then share insights on Dart's performance leap from dart2js to dart2wasm, its potential beyond the browser, and what the WasmGC transition means for developers and the broader ecosystem. Finally, they look at Jaspr, Dart-only web apps, or how different browsers are handling WasmGC. This episode again is packed with sharp technical detail and bold visions for the future of WebAssembly. Resources: Dart → https://goo.gle/4kfijgD  Flutter → https://goo.gle/4kh4jDi  Before Flutter | Rubber Duck Engineering | Episode #100 → https://goo.gle/4nujV9g  State of Developer Ecosystem Report → https://goo.gle/4lrmya6  What's new in Flutter → https://goo.gle/44xx0Gl   Dart & Flutter momentum at Google I/O 2025 → https://goo.gle/3TgUr1p  Accessibility in Flutter on the Web → https://goo.gle/4l2xfQB  Stateful hot reload in DartPad → https://goo.gle/4nokFg1  WebAssembly (Wasm) compilation → https://goo.gle/3I8Ngpx  Support for WebAssembly (Wasm) → https://goo.gle/45L0wdR  WebAssembly Garbage Collection (WasmGC) now enabled by default in Chrome → https://goo.gle/3G7qLAS  Wasm-feature-detect library → https://goo.gle/4evqS5Y  A new way to bring garbage collected programming languages efficiently to WebAssembly → https://goo.gle/4keW0rt      [dart2wasm] Support non-JS wasm runtimes → https://goo.gle/44wr3t3  Safari bug: Umbrella: Using Canvas image sources between different canvases and canvas types is slow → https://goo.gle/3TmuSvM  Firefox bug: OffscreenCanvas.transferToImageBitmap incurs a copy → https://goo.gle/3GoIGD2  Ömer Ağacan on LinkedIn → https://goo.gle/4lA6fYB Martin Kustermann on LinkedIn → https://goo.gle/3TffQbc