Pieter Levels: reverse-engineering Windows XP for the browser was ‘only possible because modern AI like Opus 5.5 is good enough’
@levelsio @levelsioX
Why it matters
First-hand account by a developer of AI-assisted reverse-engineered WASM ports, with usage numbers (142k views).
Summary
Pieter Levels (@levelsio) describes two years of ‘nostalgia projects’: Windows 3.1 in the browser, classic games such as Quake ported to WASM with multiplayer, and six months reverse-engineering Windows XP to run on v86, ‘only possible because modern AI like Opus 5.5 is good enough to figure that out’. He says the projects took off with ‘this wave of AI-assisted reverse engineering WASM ports of games and apps’, that ‘yesterday 80,000 people played around in Windows 3.1 or Windows XP inside their browsers’, and that his @pieter site is a non-commercial preservation project.
Metrics read 2026-10-12 via api.fxtwitter.com: 142,417 views, 652 likes.
Archived text
💾 Two years ago I started working on these crazy nostalgia projects, kind of randomly, because I was bored and wanted to do something different than just build another SaaS or AI app/website
I wanted to try to run Windows 3.1 inside a web browser, and to do that properly already took me months
When that worked well enough, I wanted to build a dial up internet connection so it could browse the web, with the basic levels of AI back then, that was VERY hard, and I’d just go around in circles forever. Finally I had to find the only person in the world who got that working @bai0 and beg him to help me make it work, and we did it!
Then I started hosting classic games like Quake with full multiplayer, porting them to WASM, or if not already like Quake III by @lukathedev and hosting those with a full multiplayer server ready-to-go in your browser
And then I spent 6 months trying to reverse engineer Windows XP to run on v86 by @copy_sh, very difficult (because it’s so big) and only possible because modern AI like Opus 5.5 is good enough to figure that out
For the last two years pretty much nobody cared about any of these projects, I’d tweet them into the void, which was fine because I thought it was very fun just for myself
But now with this wave of AI-assisted reverse engineering WASM ports of games and apps to web they’re finally taking off, pretty much anything is portable to WASM on web now, and if you add server to it via WebSockets, people can instantly play with each other, or interact inside apps you host, it’s super cool
Every game and app I have on @pieter now is full or almost full to the limit, yesterday 80,000 people played around in Windows 3.1 or Windows XP inside their browsers chatting to MSN and AOL Messenger AI bots and playing 3D Pinball or playing Quake etc.
And that was my idea for @pieter: a non-commercial preservation project, kinda like an online computer museum but interactive!
The most cool thing to pay respects to these old games, apps and OSes I think is to keep them alive by making them easily and freely accessible, playable on mobile so old and new generations of people can jump back in the past interactively
This is one of my first projects to take off that does not, can not and will not make money because it’s non-profit, and that’s fine
Every time I tweeted about these projects would always ask me “but why?”
Because it’s really fun! 🤩
Quoting @RadiantOpti: PLAY ALL THESE GAMES IN YOUR BROWSER
Your PC does not need the game installed!
you can play Black Ops zombies, Skate 3, Halo and MW2 and more GAMES all run in a browser tab now. full list in the comments.
School gaming is boutta be fire
