CheerpX: a WebAssembly-based x86 virtual machine in the browser, Yuri Iozzelli
Why Hacker News recommends it
HN points to it as an impressive look at how far WebAssembly can go, and as the explanation of the architecture behind CheerpX and its Flash support.
What it is
A talk by Yuri Iozzelli at a WebAssembly meetup on CheerpX, an x86 virtual machine running in the browser. It uses a JIT compiler that emits WebAssembly at runtime to run real native applications. It covers the architecture and demos such as porting a multiplayer C++ game.
Recommended by 2 HN commenters across 3 different months, 2020 to 2025.
What Hacker News said
Strong rec gavinray · 2022-03 · on “PartialExecuter: Reducing WebAssembly size by exploring all executions in LLVM”
This company has an x86-to-WASM compiler that lets you execute arbitrary binaries in the browser. Also a JVM to WASM transpiler. There's a fantastic Meetup presentation given by one of them where they show running a C++ multiplayer game with both client AND server running in a browser, using WebRTC as a networking polyfill. Really mindblowing: [this video]
Recommends btown · 2020-06 · on “Adobe to remove Flash Player from web site after December 2020”
Here's a talk by the team as well: [this video] And their website: [LINK] This is honestly one of the coolest things I've seen, and given the amount of Flex/Spark software for enterprise out there, it could drastically change the legacy software landscape.
Recommends gavinray · 2025-03 · on “Browsercraft: Java Minecraft in the browser”
5 years ago, I watched a YouTube recording of a meetup talk given by one of the CheerpX engineers: [this video] In it, they showed a functional demo of porting an OSS multiplayer C++ game entirely to the browser with WASM. Afterwards, I read some of their engineering content and was blown away. It's been fascinating to watch the CheerpX/CheerpJ progress from afar over the years.
Cites apignotti · 2020-07 · on “Flash Game History”
At Leaning Technologies, we are working on preserving _all_ flash content by running the original x86 Flash plugin via WebAssembly virtualization (CheerpX). If you want to read more: [LINK] [LINK] A presentation about the architecture of the system: [this video] Feel free to drop me any question: [LINK]
Cites saagarjha · 2020-10 · on “iSH Shell”
It's been on our minds for a while, the major issues with this is that IPC between the app process and WebKit is like 100µs, so having the interpreter run isolated from the app process is hard. Plus loading WASM is not "free" (that is, essentially an instruction cache flush) because you need to generate a bundle that WebKit will then load, which is slow (although there has been work done in this area: [this video] ). So even if we did some sort of WASI thing where everything is going on in the browser, there are hurdles to overcome to make this viable. Plus the current interpreter almost certainly leaves performance on the table ;)
Cites nanaian · 2023-10 · on “Ruffle: Flash Player Emulator”
Developer here. CheerpX for Flash runs the Pepper API version of Flash, and you're correct about the license. However, we don't do full Linux emulation just to run Flash - we emulate PPAPI and run the Flash player in an x86 JIT (CheerpX). Yuri talks about CXFF's architecture here: [this video] ...but if you wanted full Linux system emulation, we got it! [LINK]