A highly portable open source IA-32 (x86) PC emulator written in C++, that runs on most popular platforms.
A portable x86 PC emulation software package
A portable x86 PC emulation software package with gdbstub
A portable x86 PC emulation software package, including GUI debugger
An open-source IA-32 (x86) PC emulator
Bochs Project x86 PC Emulator(2)
Bochs is a powerful x86/amd64 hardware emulation and debugger software.
Besides the CPU and instruct set extensions, it simulates common PC/AT
hardware, an ISA and PCI system bus, memory, disks, video hardware,
ethernet, and enough of a compatible BIOS to run DOS/Winows, Linux/BSD,
Minix and other operating systems.
It doesn't provide virtualization, thus runs extremely slow, but is safe
to run for the host operating system.
Emulator for x86 PC
Highly portable open source IA-32 (x86) PC emulator
IA-32 (x86) PC emulator that runs DOS, Win 95, and more
IA32 and AMD64 PC emulator
LGPL-ed pc emulator
Open source IA-32 (x86) PC emulator written in C++