I've just installed ReactOS-3.4 as a guest OS on a Fedora 9 Host running VBox 1.6.0. It was a very fast install and for those unfamiliar with ReactOS, think Windows XP with a little Linux injected into it. You can find it at www.reactos.org
. Warning, it is still in Alpha stages and is definitely not ready for primetime. It appears to be a free windows clone, although it only supports DOS FS and not NTFS yet. I set up my VM with 128MB RAM, the default 8MB video RAM and a fixed 4GB vdi. The current problem I have are the drivers for the INTEL 82441FX Pentium Pro Processor to PCI bridge and the Intel 82371SB PCI to ISA bridge. The code is supposed to be M$ compat, allowing you to run sftwe for Windows, so maybe I might just try installing the Guest Additions for Windows and see if that works. Otherwise the system randomly gives the equivalent of the infamous BSOD. If it works than their is another OS that can be run as a guest. I'll post later with results.