Wrote a blog post about the work I've been doing at @igalia.com to implement the Temporal proposal in JavaScriptCore:
blogs.igalia.com/compilers/20...
blogs.igalia.com/compilers/20...
Implementing the Temporal proposal in JavaScriptCore
Implementing the Temporal proposal for date and time handling in JavaScript in JavaScriptCore, the JavaScript engine in WebKit
blogs.igalia.com
February 2, 2026 at 8:53 PM
Wrote a blog post about the work I've been doing at @igalia.com to implement the Temporal proposal in JavaScriptCore:
blogs.igalia.com/compilers/20...
blogs.igalia.com/compilers/20...
I am once again reading the JavaScriptCore bible phrack.org/issues/70/3....
.:: Phrack Magazine ::.
Phrack staff website.
phrack.org
October 3, 2024 at 12:40 AM
I am once again reading the JavaScriptCore bible phrack.org/issues/70/3....
Believe it or not I'm still hiring: jobs.apple.com/en-us/detail...
JavaScriptCore Security Engineer - Jobs - Careers at Apple
Apply for a JavaScriptCore Security Engineer job at Apple. Read about the role and find out if it’s right for you.
jobs.apple.com
November 14, 2025 at 9:43 PM
Believe it or not I'm still hiring: jobs.apple.com/en-us/detail...
Make Sure to Update: iOS 18.1.1 and macOS Sequoia 15.1.1 Fix Actively Exploited Vulnerabilities
Make Sure to Update: iOS 18.1.1 and macOS Sequoia 15.1.1 Fix Actively Exploited Vulnerabilities
The iOS 18.1.1, iPadOS 18.1.1, and macOS Sequoia 15.1.1 updates that Apple released today address JavaScriptCore and WebKit vulnerabilities that Apple says have been actively exploited on some devices.
With the JavaScriptCore vulnerability,…
www.macrumors.com
November 19, 2024 at 7:03 PM
Make Sure to Update: iOS 18.1.1 and macOS Sequoia 15.1.1 Fix Actively Exploited Vulnerabilities
I built my own JavaScript runtime in OCaml
I wanted to see how far OCaml could go against Bun and Node, and also also OCaml vs zig vs c++ in similar APIs.
So I built `sirocco`.
Uses JavaScriptCore (same engine as Bun and Safari). Event loop with libuv and it's written in OxCaml.
I wanted to see how far OCaml could go against Bun and Node, and also also OCaml vs zig vs c++ in similar APIs.
So I built `sirocco`.
Uses JavaScriptCore (same engine as Bun and Safari). Event loop with libuv and it's written in OxCaml.
January 2, 2026 at 3:08 PM
I built my own JavaScript runtime in OCaml
I wanted to see how far OCaml could go against Bun and Node, and also also OCaml vs zig vs c++ in similar APIs.
So I built `sirocco`.
Uses JavaScriptCore (same engine as Bun and Safari). Event loop with libuv and it's written in OxCaml.
I wanted to see how far OCaml could go against Bun and Node, and also also OCaml vs zig vs c++ in similar APIs.
So I built `sirocco`.
Uses JavaScriptCore (same engine as Bun and Safari). Event loop with libuv and it's written in OxCaml.
O novo JIT do JavaScriptCore se chama.... LOL
December 24, 2025 at 11:06 PM
O novo JIT do JavaScriptCore se chama.... LOL
Community-Maintained JavaScriptCore: The JavaScriptCore (JSC) engine has moved to a community-maintained package.
If your app relies on JSC, you'll need to use this separate package to upgrade to 0.81. This doesn't affect apps using Hermes!
github.com/react-native...
If your app relies on JSC, you'll need to use this separate package to upgrade to 0.81. This doesn't affect apps using Hermes!
github.com/react-native...
GitHub - react-native-community/javascriptcore: JavaScriptCore for React Native
JavaScriptCore for React Native . Contribute to react-native-community/javascriptcore development by creating an account on GitHub.
github.com
August 12, 2025 at 4:18 PM
Community-Maintained JavaScriptCore: The JavaScriptCore (JSC) engine has moved to a community-maintained package.
If your app relies on JSC, you'll need to use this separate package to upgrade to 0.81. This doesn't affect apps using Hermes!
github.com/react-native...
If your app relies on JSC, you'll need to use this separate package to upgrade to 0.81. This doesn't affect apps using Hermes!
github.com/react-native...
We're hiring JavaScriptCore VM engineers in Cupertino, CA. Good opportunity to work on some truly foundational tech that underpins web performance in Apple products.
jobs.apple.com/en-us/detail...
jobs.apple.com/en-us/detail...
JavaScript Virtual Machine Compiler Engineer - Jobs - Careers at Apple
Apply for a JavaScript Virtual Machine Compiler Engineer job at Apple. Read about the role and find out if it’s right for you.
jobs.apple.com
July 3, 2025 at 4:38 AM
We're hiring JavaScriptCore VM engineers in Cupertino, CA. Good opportunity to work on some truly foundational tech that underpins web performance in Apple products.
jobs.apple.com/en-us/detail...
jobs.apple.com/en-us/detail...
TIL that javascriptcore has a state in which it is having a bad time https://github.com/WebKit/WebKit/blob/2377cad7def2fcc31b330c4950e1c98efae80549/Source/JavaScriptCore/runtime/JSGlobalObject.cpp#L2785
July 10, 2026 at 12:07 PM
TIL that javascriptcore has a state in which it is having a bad time https://github.com/WebKit/WebKit/blob/2377cad7def2fcc31b330c4950e1c98efae80549/Source/JavaScriptCore/runtime/JSGlobalObject.cpp#L2785
We, Apple JavaScriptCore team, are hiring a senior stability engineer, focusing on stability of JavaScriptCore. If you are interested, submit resume via the URL! Let's make JavaScriptCore steady and rock solid! #WebKit #Apple jobs.apple.com/en-us/detail...
Senior JavaScript Virtual Machine Stability Engineer - Careers at Apple
Apply for a Senior JavaScript Virtual Machine Stability Engineer job at Apple. Read about the role and find out if it’s right for you.
jobs.apple.com
November 20, 2024 at 6:45 PM
We, Apple JavaScriptCore team, are hiring a senior stability engineer, focusing on stability of JavaScriptCore. If you are interested, submit resume via the URL! Let's make JavaScriptCore steady and rock solid! #WebKit #Apple jobs.apple.com/en-us/detail...
sosukesuzukiさんも書いていたが、現実逃避としてのOSS活動という行動類型がある 実際に意義ある貢献ではあるだけになおさらタチが悪い
> やりたくないことがあるときに現実逃避としてJavaScriptCoreに貢献しているきらいがある
sosukesuzuki.dev/posts/jsc-co...
> やりたくないことがあるときに現実逃避としてJavaScriptCoreに貢献しているきらいがある
sosukesuzuki.dev/posts/jsc-co...
WebKit(JavaScriptCore)に100個のPull Requestがマージされた
sosukesuzuki's personal website
sosukesuzuki.dev
August 15, 2025 at 8:59 AM
sosukesuzukiさんも書いていたが、現実逃避としてのOSS活動という行動類型がある 実際に意義ある貢献ではあるだけになおさらタチが悪い
> やりたくないことがあるときに現実逃避としてJavaScriptCoreに貢献しているきらいがある
sosukesuzuki.dev/posts/jsc-co...
> やりたくないことがあるときに現実逃避としてJavaScriptCoreに貢献しているきらいがある
sosukesuzuki.dev/posts/jsc-co...
A Brief JavaScriptCore RCE Story:
qriousec.github.io/post/jsc-uni...
#cybersecurity #informationsecurity #rce #javascript #vulnerability
qriousec.github.io/post/jsc-uni...
#cybersecurity #informationsecurity #rce #javascript #vulnerability
January 19, 2025 at 2:31 PM
A Brief JavaScriptCore RCE Story:
qriousec.github.io/post/jsc-uni...
#cybersecurity #informationsecurity #rce #javascript #vulnerability
qriousec.github.io/post/jsc-uni...
#cybersecurity #informationsecurity #rce #javascript #vulnerability
JSC is moving to a community package
Starting with React Native 0.79, JavaScriptCore (JSC) is moving to `@react-native-community/javascriptcore`
This allows for more frequent updates and latest features, while reducing React Native's API surface. Don't worry — this won't affect Hermes users!
Starting with React Native 0.79, JavaScriptCore (JSC) is moving to `@react-native-community/javascriptcore`
This allows for more frequent updates and latest features, while reducing React Native's API surface. Don't worry — this won't affect Hermes users!
GitHub - react-native-community/javascriptcore: JavaScriptCore for React Native
JavaScriptCore for React Native . Contribute to react-native-community/javascriptcore development by creating an account on GitHub.
github.com
April 8, 2025 at 1:22 PM
JSC is moving to a community package
Starting with React Native 0.79, JavaScriptCore (JSC) is moving to `@react-native-community/javascriptcore`
This allows for more frequent updates and latest features, while reducing React Native's API surface. Don't worry — this won't affect Hermes users!
Starting with React Native 0.79, JavaScriptCore (JSC) is moving to `@react-native-community/javascriptcore`
This allows for more frequent updates and latest features, while reducing React Native's API surface. Don't worry — this won't affect Hermes users!
🍎⚠️ Alert: Apple Safari JavaScriptCore vulnerability CVE-2024-44308 exploited in the wild! Affects iOS, visionOS, and macOS.
#CyberSecurity #Apple #ZeroDay #Exploit - Heads 🆙
gbhackers.com/apple-safari...
#CyberSecurity #Apple #ZeroDay #Exploit - Heads 🆙
gbhackers.com/apple-safari...
Apple Safari JavaScriptCore Remote Code Execution Flaw Exploited in the Wild
A critical vulnerability identified as CVE-2024-44308 has been actively exploited in the wild, affecting multiple versions of Apple Safari.
gbhackers.com
December 2, 2024 at 2:05 PM
🍎⚠️ Alert: Apple Safari JavaScriptCore vulnerability CVE-2024-44308 exploited in the wild! Affects iOS, visionOS, and macOS.
#CyberSecurity #Apple #ZeroDay #Exploit - Heads 🆙
gbhackers.com/apple-safari...
#CyberSecurity #Apple #ZeroDay #Exploit - Heads 🆙
gbhackers.com/apple-safari...
Hi! I’m working on improving #WebAssembly support in JavaScriptCore, the JS/Wasm engine used by WebKit / Safari and @bun.sh.
If you run into any issues or bugs, please file a report: bugs.webkit.org/enter_bug.cg... or message me.
If you run into any issues or bugs, please file a report: bugs.webkit.org/enter_bug.cg... or message me.
Log in to Bugzilla
bugs.webkit.org
August 20, 2026 at 5:35 PM
Hi! I’m working on improving #WebAssembly support in JavaScriptCore, the JS/Wasm engine used by WebKit / Safari and @bun.sh.
If you run into any issues or bugs, please file a report: bugs.webkit.org/enter_bug.cg... or message me.
If you run into any issues or bugs, please file a report: bugs.webkit.org/enter_bug.cg... or message me.
We care deeply about the experience people have when using Safari. And we care about the experience people have when using any of the millions of iOS, iPadOS, macOS, visionOS, and watchOS apps that are built using WebKit and JavaScriptCore.
March 24, 2026 at 6:16 PM
We care deeply about the experience people have when using Safari. And we care about the experience people have when using any of the millions of iOS, iPadOS, macOS, visionOS, and watchOS apps that are built using WebKit and JavaScriptCore.
Come work with me at Igalia! We're hiring a programming languages engineer to primarily work on JavaScript standardization and specification. Igalia is a worker-owned cooperative and all jobs are 100% remote.
www.igalia.com/jobs/javascr...
www.igalia.com/jobs/javascr...
JavaScript Engine Developer | Igalia - Open Source Consultancy and Development
The Igalia's compilers team works across a broad range of technologies. One such technology is JavaScript engines, where the team contributes to compilers and runtimes including V8, JavaScriptCore, Sp...
www.igalia.com
October 10, 2025 at 5:36 PM
Come work with me at Igalia! We're hiring a programming languages engineer to primarily work on JavaScript standardization and specification. Igalia is a worker-owned cooperative and all jobs are 100% remote.
www.igalia.com/jobs/javascr...
www.igalia.com/jobs/javascr...
While chromium forked KHTML for Blink at least they made their own JS engine; V8.
Safari straight up joinked both KHTML and KJS and turned them into WebKit and JavaScriptCore respectively.
Safari is just Konqueror++
or maybe Objective-Konqueror, because you know... Apple.
Safari straight up joinked both KHTML and KJS and turned them into WebKit and JavaScriptCore respectively.
Safari is just Konqueror++
or maybe Objective-Konqueror, because you know... Apple.
June 2, 2026 at 5:59 AM
While chromium forked KHTML for Blink at least they made their own JS engine; V8.
Safari straight up joinked both KHTML and KJS and turned them into WebKit and JavaScriptCore respectively.
Safari is just Konqueror++
or maybe Objective-Konqueror, because you know... Apple.
Safari straight up joinked both KHTML and KJS and turned them into WebKit and JavaScriptCore respectively.
Safari is just Konqueror++
or maybe Objective-Konqueror, because you know... Apple.
Another option might be to compile a tail-call-optimizing JS engine to wasm and run in that.
I'm not sure if QuickJS supports tail calls, but JavaScriptCore could work in theory... and it has been ported,
mbbill.github.io/JSC.js/
I'm not sure if QuickJS supports tail calls, but JavaScriptCore could work in theory... and it has been ported,
mbbill.github.io/JSC.js/
JSC.js
JavaScriptCore on WebAssembly
mbbill.github.io
September 17, 2025 at 5:42 PM
Another option might be to compile a tail-call-optimizing JS engine to wasm and run in that.
I'm not sure if QuickJS supports tail calls, but JavaScriptCore could work in theory... and it has been ported,
mbbill.github.io/JSC.js/
I'm not sure if QuickJS supports tail calls, but JavaScriptCore could work in theory... and it has been ported,
mbbill.github.io/JSC.js/
Not just that, but for the first 5 years or so of Chrome it directly used WebCore (with V8 replacing JavaScriptCore). It wasn't til Chrome 28 that they forked it to create Blink.
June 2, 2026 at 6:48 AM
Not just that, but for the first 5 years or so of Chrome it directly used WebCore (with V8 replacing JavaScriptCore). It wasn't til Chrome 28 that they forked it to create Blink.
note it’s not porting the JS engine. Bun is a (very big) wrapper around WebKit’s JavaScriptCore
May 7, 2026 at 5:38 AM
note it’s not porting the JS engine. Bun is a (very big) wrapper around WebKit’s JavaScriptCore
CVE-2024-44308: remote code execution in JavaScriptCore (web-based attack), affecting macOS Sequoia, iPadOS, iOS, and visionOS.
See Apple's security releases for more: support.apple.com/en-us/100100
See Apple's security releases for more: support.apple.com/en-us/100100
Apple security releases - Apple Support
This document lists security updates and Rapid Security Responses for Apple software.
support.apple.com
November 19, 2024 at 9:06 PM
CVE-2024-44308: remote code execution in JavaScriptCore (web-based attack), affecting macOS Sequoia, iPadOS, iOS, and visionOS.
See Apple's security releases for more: support.apple.com/en-us/100100
See Apple's security releases for more: support.apple.com/en-us/100100