こんにちは。虎の穴ラボのH.Hです。 今回は先日発表されたChromeの開発中の新機能であるRecorder機能について使用方法や利用する際の注意点などをまとめました。 Recoder機能とは ブラウザのChrome97で追加される予定の機能で、ブラウザの画面上で操作した記録を取得してくれる機能になります。 この記事を書いている2021年11月17日では一般に提供されているChromeの最新版は96となり、開発中の「Chrome Dev」もしくは「Chrome Canary」でRecorder機能を使用することができます。 利用している時の様子はChromeの開発者向けのページに公開されています。 developer.chrome.com 主な機能は以下の通りです。 ・操作の記録及び再実行(リプレイ)できる ・再実行時にパフォーマンスの記録・確認できる ・記録した内容の編集ができる ・操作
REST API Design Best Practices Handbook – How to Build a REST API with JavaScript, Node.js, and Express.js
By Jean-Marc Möckel I've created and consumed many API's over the past few years. During that time, I've come across good and bad practices and have experienced nasty situations when consuming and building API's. But there also have been great moments. There are helpful articles online which present many best practices, but many of them lack some practicality in my opinion. Knowing the theory with
WebKit Features in Safari 16.4
Mar 27, 2023 by Patrick Angle, Marcos Caceres, Razvan Caliman, Jon Davis, Brady Eidson, Timothy Hatcher, Ryosuke Niwa, and Jen Simmons ContentsWeb Push on iOS and iPadOSImprovements for Web AppsWeb ComponentsCSSHTMLJavaScript and WebAssemblyWeb APIImages, Video, and AudioWKWebViewDeveloper ToolingWeb InspectorSafari Web ExtensionsSafari Content BlockersNew Restrictions in Lockdown ModeMore Improve
GitHub - modelcontextprotocol/servers: Model Context Protocol Servers
Official integrations are maintained by companies building production ready MCP servers for their platforms. 21st.dev Magic - Create crafted UI components inspired by the best 21st.dev design engineers. 2slides - An MCP server that provides tools to convert content into slides/PPT/presentation or generate slides/PPT/presentation with user intention. ActionKit by Paragon - Connect to 130+ SaaS inte
What's New In DevTools (Chrome 94) | Blog | Chrome for Developers
Use DevTools in your preferred language Chrome DevTools now supports more than 80 languages, allowing you to work in your preferred language! Open Settings, then select your preferred language under the Preferences > Language dropdown and reload DevTools. Preferences" width="800" height="494"> Chromium issue: 1163928 New Nest Hub devices in the Device list You can now simulate the dimensions of Ne
Introducing Ezno
Ezno is an experimental compiler I have been working on and off for a while. In short, it is a JavaScript compiler featuring checking, correctness and performance for building full-stack (rendering on the client and server) websites. This post is just an overview of some of the features I have been working on which I think are quite cool as well an overview on the project philosophy ;) It is still
I was continueing my exploration of React server components when I stumbled upon on this article about progressive JSON. Dan Abramov describes a technique for streaming JSON from a server to a client in chunks, allowing the client to start rendering parts of the data before the entire payload has been received. This can significantly improve perceived performance, especially for large datasets. So
LogLog Games
The article is also available in Chinese. Disclaimer: This post is a very long collection of thoughts and problems I've had over the years, and also addresses some of the arguments I've been repeatedly told. This post expresses my opinion the has been formed over using Rust for gamedev for many thousands of hours over many years, and multiple finished games. This isn't meant to brag or indicate su
Assessing Claude Mythos Preview’s cybersecurity capabilities April 7, 2026 Nicholas Carlini, Newton Cheng, Keane Lucas, Michael Moore, Milad Nasr, Vinay Prabhushankar, Winnie Xiao Hakeem Angulu, Evyatar Ben Asher, Jackie Bow, Keir Bradwell, Ben Buchanan, David Forsythe, Daniel Freeman, Alex Gaynor, Xinyang Ge, Logan Graham, Kyla Guru, Hasnain Lakhani, Matt McNiece, Mojtaba Mehrara, Renee Nichol, A
In this post I’ll walk through the full implementation of a Virtual DOM in a bit over 200 lines of JavaScript. The result is a full-featured and sufficiently performant virtual DOM library (demos). It’s available on NPM as the smvc package. The main goal is to illustrate the fundamental technique behind tools like React. React, Vue and the Elm language all simplify the creation of interactive web
Today we’re excited to announce the release of TypeScript 5.2! If you’re not familiar with TypeScript, it’s a language that builds on top of JavaScript by making it possible to declare and describe types. Writing types in our code allows us to explain intent and have other tools check our code to catch mistakes like typos, issues with null and undefined, and more. Types also power TypeScript’s edi
9 Times the Web Platform Was Influenced by Libraries | Jad Joubran
The web platform didn't invent most of its best APIs. It caught up to them. Libraries did the R&D work in production. They got tested by thousands of developers across thousands of codebases, which is the kind of feedback you can't simulate. They got bug reports. They iterated. And, the patterns that survived eventually became part of the platform itself. If you've been writing JavaScript for a wh
On January 14, 2006, John Resig introduced a JavaScript library called jQuery at BarCamp in New York City. Now, 20 years later, the jQuery team is happy to announce the final release of jQuery 4.0.0. After a long development cycle and several pre-releases, jQuery 4.0.0 brings many improvements and modernizations. It is the first major version release in almost 10 years and includes some breaking c
Object Structure in JavaScript EnginesFrom a developer's perspective, objects in JavaScript are quite flexible and understandable. We can add, remove, and modify object properties on our own. However, few people think about how objects are stored in memory and processed by JS engines. Can a developer's actions, directly or indirectly, impact performance and memory consumption? Let's try to delve i
All JavaScript and TypeScript Features of the last 3 years
TypeScript as envisioned by Stable DiffusionThis article goes through almost all of the changes of the last 3 years (and some from earlier) in JavaScript / ECMAScript and TypeScript . Not all of the following features will be relevant to you or even practical, but they should instead serve to show what’s possible and to deepen your understanding of these languages. There are a lot of TypeScript fe
AST vs. Bytecode: Interpreters in the Age of Meta-Compilation
233 AST vs. Bytecode: Interpreters in the Age of Meta-Compilation OCTAVE LAROSE, University of Kent, UK SOPHIE KALEBA, University of Kent, UK HUMPHREY BURCHELL, University of Kent, UK STEFAN MARR, University of Kent, UK Thanks to partial evaluation and meta-tracing, it became practical to build language implementations that reach state-of-the-art peak performance by implementing only an interprete
Today we’re excited to announce our Release Candidate of TypeScript 5.2! Between now and the stable release of TypeScript 5.2, we expect no further changes apart from critical bug fixes. To get started using the RC, you can get it through NuGet, or through npm with the following command: npm install -D typescript@rc Here’s a quick list of what’s new in TypeScript 5.2! using Declarations and Explic
The product https://joinmastodon.org Mastodon is a free, open-source social network server based on ActivityPub where users can follow friends and discover new ones. On Mastodon, users can publish anything they want: links, pictures, text, and video. All Mastodon servers are interoperable as a federated network. Open source The project is open source at https://github.com/mastodon/mastodon License
Introduction to Spherical Harmonics for Graphics Programmers
This post requires JavaScript to properly render mathematics (like $\int f(x) dx$, $Y_\ell^m$). It's not likely to work in your browser's "reader mode". On your computer graphics journey, you will eventually run into some paper or code mentioning spherical harmonic functions. They are indeed a very useful tool: with just a few coefficients, they allow us to approximate a given function defined on
WebGPU is an upcoming Web API that gives you low-level, general-purpose access GPUs. I am not very experienced with graphics. I picked up bits and bobs of WebGL by reading through tutorials on how to build game engines with OpenGL and learned more about shaders by watching Inigo Quilez do amazing things on ShaderToy by just using shaders, without any 3D meshes or models. This got me far enough to
Introduction HTML, the programming language, is a practical, turing-complete[1], stack-based programming language based on HTML, the markup language. It uses elements defined in HTML, the markup language, in order to do computations. To give you a sense of what HTML, the programming langauge, looks like, below is a sample program that prints the values from 1 to 10 to standard out (console.log) A
Nx Console VS Code Extension Compromised - StepSecurity
Update: On May 19, 2026, GitHub publicly disclosed that approximately 3,800 of its internal source code repositories were exfiltrated after an employee's device was compromised by a poisoned VS Code extension. While GitHub did not officially name the extension, Nx CEO Jeff Cross confirmed that Nx is working with Microsoft and GitHub on the impact of the malicious Nx Console version 18.95.0, and no
Use Thunder Client and VSCode as an alternative to Postman
Visual Studio Code (VSCode) is a popular code editor that can be used as an alternative to Postman for API testing. With the right extensions, developers can easily create, manage, and test APIs within the VSCode environment. Using Thunder Client with VSCode for API testing can streamline the development workflow and save time by using a single tool for coding and testing, as this article will sho
Jun 9, 2025 by Jen Simmons, Saron Yitbarek, Jon Davis, Richard Robinson, Eddy Wong, Brandel Zachernuk, Marcos Cáceres, Tim Nguyen, Daniel Liu, Razvan Caliman, Blaze Burg, Qianlang Chen, Brian Weinstein, Aditya Keerthi, Karl Dubost, David Johnson, Luming Yin ContentsSVG IconsEvery site can be a web app on iOS and iPadOSHDR ImagesWebKit in SwiftUI<model> on visionOSImmersive video and audio on visio
WebKit Features in Safari 17.2
ContentsHTMLCSSImages and videoJavaScriptWeb APIWeb AppsWebGLPrivacyWeb InspectorFixes for Interop 2023 and moreUpdating to Safari 17.2Feedback Web technology is constantly moving forward, with both big new features and small subtle adjustments. Nowadays, web developers expect web browsers to update multiple times a year, instead of the once or twice a year typical of the late 2000s — or the once
I’ve been trying to write this post at least a dozen times. I don’t mean this figuratively; at one point, I literally had a desktop folder with a dozen abandoned drafts. They had wildly different styles—from rigoruous to chaotically cryptic and insufferably meta; they would start abruptly, chew on themselves, and eventually trail off to nowhere. One by one, I threw them all away because they all s
Debug memory leaks with the Microsoft Edge Detached Elements tool
Debug memory leaks with the Microsoft Edge Detached Elements tool Memory leaks occur when the JavaScript code of an application retains more and more objects in memory that it doesn’t need any longer instead of releasing them for the browser to garbage collect (GC). For long-running apps, small memory leaks of only a few kilobytes can add up to noticeably degrade performance over time. Web develop
MAI-Thinking-1: Building a Hill-Climbing Machine The Microsoft AI Team 1 Abstract Progress in AI is driven not by a single model, but by the ability to continually improve upon the current state of models. Achieving this requires treating model development as a system-level optimization problem, for which the solution is building a hill-climbing machine for rapid improvement. Our process includes
WebKit Features in Safari 18.4
Mar 31, 2025 by Jen Simmons, Saron Yitbarek, Jon Davis, Razvan Caliman, Karl Dubost, Brady Eidson, Elika Etemad, Youenn Fablet, Matthew Finkel, Simon Fraser, Timothy Hatcher, David Johnson, Anne van Kesteren, Daniel Liu, Keith Miller, Rupin Mittal, Tim Nguyen, Pascoe, Abrar Rahman Protyasha, Richard Robinson, Lily Spiniolas, Brandon Stewart, John Wilander and Luming Yin ContentsDeclarative Web Pus
Local-first software: You own your data, in spite of the cloud
Cloud apps like Google Docs and Trello are popular because they enable real-time collaboration with colleagues, and they make it easy for us to access our work from all of our devices. However, by centralizing data storage on servers, cloud apps also take away ownership and agency from users. If a service shuts down, the software stops functioning, and data created with that software is lost. In t
25th May 2025 Anthropic publish most of the system prompts for their chat models as part of their release notes. They recently shared the new prompts for both Claude Opus 4 and Claude Sonnet 4. I enjoyed digging through the prompts, since they act as a sort of unofficial manual for how best to use these tools. Here are my highlights, including a dive into the leaked tool prompts that Anthropic did
Today we are excited to announce the availability of TypeScript 5.2 Beta. To get started using the beta, you can get it through NuGet, or through npm with the following command: npm install -D typescript@beta Here’s a quick list of what’s new in TypeScript 5.2! using Declarations and Explicit Resource Management Decorator Metadata Named and Anonymous Tuple Elements Easier Method Usage for Unions o
--- name: skill-creator description: Guide for creating effective skills. This skill should be used when users want to create a new skill (or update an existing skill) that extends Claude's capabilities with specialized knowledge, workflows, or tool integrations. license: Complete terms in LICENSE.txt --- # Skill Creator This skill provides guidance for creating effective skills. ## About Skills S
Processing Arrays non-destructively: `for-of` vs. `.reduce()` vs. `.flatMap()`
Processing Arrays non-destructively: for-of vs. .reduce() vs. .flatMap() In this blog post, we look at three ways of processing Arrays: The for-of loop The Array method .reduce() The Array method .flatMap() The goal is to help you choose between these features whenever you need to process Arrays. In case you don’t know .reduce() and .flatMap() yet, they will both be explained to you. In order to g
Let’s learn how modern JavaScript frameworks work by building one
2 Dec Let’s learn how modern JavaScript frameworks work by building one Posted December 2, 2023 by Nolan Lawson in Web. Tagged: javascript. 20 Comments In my day job, I work on a JavaScript framework (LWC). And although I’ve been working on it for almost three years, I still feel like a dilettante. When I read about what’s going on in the larger framework world, I often feel overwhelmed by all the
As I’ve been using Next.js professionally on my employer’s web app, I find the core design of their App Router and React Server Components (RSC) to be extremely frustrating. And it’s not small bugs or that the API is confusing, but large disagreements about the fundamental design decisions that Vercel and the React team made when building it. The more webdev events I go to, the more I see people w
What if you don't need MCP at all? 2025-11-02 One chonky MCP server Table of contents After months of agentic coding frenzy, Twitter is still ablaze with discussions about MCP servers. I previously did some very light benchmarking to see if Bash tools or MCP servers are better suited for a specific task. The TL;DR: both can be efficient if you take care. Unfortunately, many of the most popular MCP
Introduction: Density Is King (With a Tiny VM) I've previously come to the conclusion that there's little reason for using bytecode in the modern world, except in order to get more compact code, for which it can be very effective. So, what kind of a bytecode engine will give you more compact code? Suppose I want a bytecode interpreter for a very small programming environment, specifically to minim
Theme 第 167 回のテーマは 2024 年の Yearly Ecosystem です。 Show Note 2024 年のチェックポイント Vite の覇権を Turbopack, RSPack が奪えるか? Storybook は覇権をとって、Chromatic もすごくなりそう Next App Router が本当に広がるか RSC 対応の Bundler が増えて Next 以外の解が見れそう アプリケーションの Rust 化くるか? React Forget Figma Config 2024 の Adobe の影響 State Management どうなってく? (Context, Jotai, SWR, Signal) ESLint to flat config or Biome AI driven FE Development CSS の新しい方法論 今年のキーワ
The Alkyne GC · mcyoung
Alkyne is a scripting language I built a couple of years ago for generating configuration blobs. Its interpreter is a naive AST walker1 that uses ARC2 for memory management, so it’s pretty slow, and I’ve been gradually writing a new evaluation engine for it. This post isn’t about Alkyne itself, that’s for another day. For now, I’d like to write down some notes for the GC I wrote3 for it, and more
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Chromeに入るRecorder機能の利用と注意点 - 虎の穴ラボ技術ブログ
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