QEMU

QEMU is an open source that can create and manage virtual machines to run guest operating systems. ARM, Intel, and PowerPC are among supported hardware platforms. 68K is only supported as a guest platform.

Emulation
QEMU can employ emulation if the guest software was written for a different processor family than the host hardware. The dynamic recompiler in VirtualBox from is derived from QEMU.

Forks to run iOS devices
There have been 3 forks of QEMU related to running iOS devices in QEMU, which each of which either failed, succeeded, or partially succeeded:
 * In late 2022, internet user Martijn de Vos (known online as devos50) created an unnamed fork of QEMU to emulate the 1st-generation iPod touch using past work provided by the previous QEMU forks, iEmu, xnu-qemu-arm64, and TruEmu, as well as OpeniBoot. It can successfully boot iPhone OS 1.1, build 3A101a. Like touchHLE and clicky, the U.S. 's reverse-engineering tool was used.