Porffor goes alpha August 11th
A self-hosting and rewritten Porffor launches in SF next month!
Oliver Medhurst
Latest posts
Native-only garbage collection
Target-dependent garbage collection for the best trade-off.
Profile-guided dead code elimination
A novel approach for DCE in dynamic languages.
Porffor now has closures
Surprisingly annoying for a compiler.
Eliminating JavaScript cold starts on AWS Lambda
Porffor can run on Lambda now!
Dissecting Dia
Whether you like it or not, Dia presents a relatively novel browser user experience and is now in a publicly available beta, so I think it is worth looking into how it works. Here are some interesting day 1 findings from analyzing its binaries: Models Dia has the capability to use both locally ran and hosted models, although I'm not sure if/when the former is used. Hosted models mentioned…
JS engine code size
Quick tiny blog post for the size of many JS engines because I couldn't find it myself and took the rabbit hole of measuring them myself. Some asterisks, this was a quick measurement and I'm not saying they are exact or correct; but I think it gives a good ballpark. These sizes are just the core source of the engine, doesn't include some parts intentionally (eg shared libraries or dependencies):…
Porffor: Objects v2
Objects are now faster with 2-5x smaller Wasm binaries!
Porffor's January 2025 Goals
A more compliant and stable compiler.
Optimizing this in Porffor
this can be surprisingly bad for performance.
Porffor passes 50% of Test262
Now passing 50% of the official ECMAScript test suite!
Porffor FFI
Porffor now has experimental FFI support!
A new chapter for Porffor
From next week, I will be independently building Porffor full-time!
1 year of Porffor
My JS engine is a year old today! Let's recap.
Porffor: Halving ASCII string memory usage with ByteString
My JS engine has a new string representation, here's what/why/how.
Porffor: Type annotations for performance
My JS engine can now parse TS and use it for optimizations!
Porffor: v0.2 rewrite done!
My JS engine's months-long rewrite is finally done!
New year, new offer, same job
I have a new permanent offer with Mozilla! Plus a recap and resolutions.
Porffor: The value wrapping dilemma
My JS engine and why it is currently terrible.
Shadow Devlog #2
Table of Contents Comparisons Ladybird SunSpider Results WHATWG Performance New Debug Overlay Page Load Profiler ~3x Faster Page Load ~2x Faster Rendering Layout Pseudo-classes var() CSS Parser ~8x Faster Dead Text Node Removal Many Fixes JavaScript ~5x Faster Worker Execution Loop New APIs HTML Parser Attributes Without Value Autofix Mismatching Closing Tags Welcome to the second Shadow devlog!…
Shadow Devlog #1
Table of Contents JavaScript Slaying the Kraken 🐙 Comparisions SerenityOS: 2nd birthday page Kraken: Start page Layout Text Wrapping CSS Selectors Rewrite External Stylesheets margin: auto Beginning of <iframe> color-scheme Rewritten <img> position: absolute text-align <br> Tweaks Misc HTML Parser Improvements Loading Non-HTML Welcome to the first Shadow devlog! If you aren't aware, Shadow is my…
Introducing Shadow
Shadow is a new novel browser engine written in JS!
Joining Mozilla
On October 1st, I join Mozilla to work on Firefox full-time!
Discord 0-click XSS to RCE
IPC allowlist bypass and setting a malicious update endpoint.
Discord 1-click XSS to RCE
Path traversal leading to Node execution from Electron's browser.