kvm, for one. Not quite as featureful, and the UI is a command line (though there's the virt manager stuff that I haven't tried). But it's rock solid virtualization that never gives me problems.
I think people are misunderstanding this thread. This is a kernel developers thread, where Dave Jones is complaining that virtualbox is the source of too much random corruption and arbitrary crashes in the kernel, and he's submitting a patch that "taints" the module such the presence of virtualbox gets flagged in kernel panics (and thus automated bug reports, etc..).
It's unstable software, and that taint is important information that prevents people from wasting effort chasing non-bugs in other components. No one is flaming about it vs. vmware or whatever, or telling you what to use.
>"No one is flaming about it vs. vmware or whatever, or telling you what to use."
Well saying virtualbox is garbage is pretty much flaming. It doesn't bother me but I imagine those working on virtualbox won't exactly be happy about it.
kvm is very high quality. When the SmartOS developers ported it to the OpenIndiana (or is it IllumOS? the naming is a joke) kernel, they found almost no bugs in kvm. Porting usually exposes bugs.
No it's not. It has its own set of problems. And bugs too! KVM has its pluses too, I agree, it's a VMM in kernel mode which apparently makes it faster, it is very non-intrusive to the rest of the kernel and hence got readily accepted upstream and so some might argue in that sense that it's better. But even though I have been hacking into KVM recently, for running a VM at home on my laptop/PC, I will always opt for VirtualBox for its simple ease of usage.
Can you give a few reasons from your own experience? I found it much, much easier to get Windows XP sound and USB passthrough working in virtualbox than in kvm.
Virtualbox is wonderful. Does it have bugs and need work? Of course.
What software doesn't?