Emulation and hardware virtualization software of various descriptions, most of them obsolete by now:
- Open Emu, a promising modular emulator.
- Virtual PC
- VMware
- Bochs, Plex86, DOSBox (has a Mac OS X frontend)
- twoOStwo
- QEMU (requires the tun/tap driver)
- FreeOSZoo - OS images for QEMU.
- libvncserver patches to let you connect to your VMs using VNC (why this isn't built-in to QEMU is beyond me).
PDA
- Little John Z - for Palm handhelds