v86
x86 PC emulator and x86-to-wasm JIT, running in the browser
...It simulates essential hardware components such as CPU, memory, VGA graphics, sound cards, network adapters, and storage controllers. Designed for both experimentation and embedding, v86 can be integrated into web apps or used as a standalone virtual machine environment. Overall, it provides a powerful way to explore operating systems, retro computing, and low-level system behavior directly from a web browser.