htmx 4: What's New, What Breaks, Why It's Not latest
htmx 4.0 is out: fetch() internals, explicit inheritance, no more history cache. What breaks, how to migrate, and why 2.x stays latest on npm until early 2027.
Dennis Morello
Lead Frontend Engineer based in Milan, Italy
I'm Dennis Morello, a Lead Frontend Engineer based in Milan, Italy, with over a decade of experience building clean, accessible web interfaces. I care about the details that make software feel right: performance, keyboard support, and interfaces that hold up for everyone using them.
Most of my work lives on the web platform. I write about frontend engineering here, ship open-source tools when I hit a gap worth filling, and rebuilt this very site with Astro.
What I work on
Day to day that means TypeScript, React, and increasingly Astro, with a long-running interest in web accessibility. I like the low-level corners of the platform too, the kind of thing I end up writing about here, whether that's the new HTTP QUERY method or TypeScript's rewrite in Go.
Things I've built
Defrag98, a browser simulator of the Windows 98 disk defragmenter, is the one that reached the most people: it landed on Hacker News and The Verge in 2024. I later rebuilt it from scratch for a more faithful simulation.
I maintain React Awesome Reveal, an animation library for React, and Arbor, a CLI that makes git worktrees pleasant to use. A couple of smaller things round out the list: a Markdown-for-AI Chrome extension and a compound-interest simulator.
Talks
I gave a live-coding talk, Writing Accessible Components, building an accessible accordion in React from scratch.
Writing
All postsWhy I Replaced Tailwind CSS With Vanilla CSS
I pulled Tailwind CSS out of my Astro site and rewrote it in vanilla CSS. Here's why modern CSS made the framework optional in 2026, and how I did it.
Bun Rust Rewrite: 64 Claude Agents, 535k Lines of Zig
Bun 1.4's Rust rewrite is now stable: 64 Claude agents ported 535k lines of Zig in 11 days. What it fixes, what it overclaims, who's right: Sumner or Kelley.
Get in touch
The best way to reach me is by email or on X. The footer has the rest of my links.