Virtualbox -- best kid on the block, free and full of features, if anyone knows sthg in this same software field (thts not mentioned) let me know. VMWare player -- hefty resource usage compared to vbox, has crippled feture set excluding snapshots etc. runs too many services in bg even when not used. Some claim it to be stable, Xen -- open source projrect to run vms on linux. I dont know much about it except that it doesnt run on windows and that it applies a concept of paravirtualization tht requires the guest OS 's kernel to be modified in order for it to work. Sthg microsoft have no interest in doing. Linux guests seems to work fine though. Dont know if this could be a viable candidate for a vbox alternative. Qemu -- After hours of research I still dont get what this program does compared to vbox or which one is better. Is it full virtualization or just paravirtualization? Is it feature rich and fast? I know its free and that some features have been incorporated in vbox. Someone experienced fill me in on this and please clarify how it works compared to the beloved vbox. If anyone has other suggestions for virtual machines softs go ahead and post about it, but only if its free please. I know vbox is great but I am open to alternatives and suggestions just incase sthg causes us to change horses in the future.