Definition
Plain language
Open-source software that emulates a computer so you can run another operating system inside it.
As stated in the literature
A widely used machine emulator and virtualizer used to run isolated guest operating systems, often for sandboxing or fuzzing.
Why it matters: It's the standard way to give untrusted code or AI agents a realistic computer to play in while keeping the real machine safe.
For example, a security researcher can use QEMU to boot a suspicious Windows binary inside a Linux machine without risking the host system.
Heard on the show
“The server compiles it, deploys it onto a Windows VM running under QEMU, executes it against the live service, and any crash is captured by an attached debugger — WinDbg.”Episode 024 — An AI Agent That Found 28 Zero-Days in Windows — And What Made It Work