Web site: www.qemu.org
Category: Machine Emulators
Platform: Linux, OS X, Windows, BSD, BeOS
License: GNU GPL
Interface: CLI
Wikipedia: QEMU
First release: 2003
QEMU – a fast emulator written by Fabrice Bellard and available as free software.
QEMU allows you to run multiple operating systems simultaneously on a single machine. It is similar to projects such as Bochs or PearPC, but has a few features (such as greater speed and support for multiple CPU architectures) that put it ahead of its competitors.
QEMU can be used in several different ways. The most common is for System Emulation, where it provides a virtual model of an entire machine (CPU, memory and emulated devices) to run a guest OS. In this mode the CPU may be fully emulated, or it may work with a hypervisor such as KVM, Xen or Hypervisor.Framework to allow the guest to run directly on the host CPU.
The second supported way to use QEMU is User Mode Emulation, where QEMU can launch processes compiled for one CPU on another CPU. In this mode the CPU is always emulated.
QEMU also provides a number of standalone command line utilities, such as the qemu-img disk image utility that allows you to create, convert and modify disk images.
Most of the program is based on the LGPL license, and the emulation part itself is on the GNU GPL.
Since February 6, 2007, the kqemu module (speeding up QEMU about 5 times) is also available on the GNU GPL license. Previously, this module was free, but the author did not want to release the source code until he received some unspecified financial compensation. In parallel, an open-source equivalent of this module, qvm86, was also developed, but due to the release of VirtualBox on the GNU GPL license, this project was closed in early 2007.
