Note that Virtual PC Express is different from Virtual PC - it's a cut down version of VPC that MS announced (but have not yet released) as an add-on for Vista. I suspect that now that Virtual PC is free (and VPC 2007) that Virtual PC Express will probably disappear as a Vista add-on feature.
I hope VMware can continue to make a go of it - they have some great technology. Whether MS is doing anything illegal or wrong, I have my own not-so-strong opinons. It's clear that they certainly have the capacity to make life very, very difficult for anyone they'd like to see out of the way, and there are times I wish the field were a bit more level. But, I do like the free software (until MS decides there's no more competition, so stops development themselves, as was the case for many years with IE 6 until Firefox came along and lit a fire under them).
Anyway, here's a catalog of free virtual machine software:
- MS Virtual Server Enterprise: http://www.microsoft.com/windowsserversystem/virtualserver/software/privacy.mspx
- MS Virtual PC: http://www.microsoft...1&displaylang=en
- VMware Player (this is really not equivalent to VMware Workstation, but nice for deploying pre-configured VMs): http://www.vmware.com/products/player/
- VMware Server (basically the next version of GSX Server): http://www.vmware.com/products/server/
- Xen (open source). I think this is currently for Linux only (as host and VM guest), but with new CPU virtualization support they will be able to host Windows (or any OS) as a guest: http://www.xensource.com/
- QEMU (mostly open source): http://fabrice.bellard.free.fr/qemu/
I think that most users will find MS Virtual PC to be the most straightforward to install and use.
I happen to use VMware Workstation because I already have it (bought it quite a while ago). It has some very nice features above VPC (for me, snapshots and 'teams') which are very usedful for development and testing, but unless you know you need those features VPC is pretty much just as good.
Interestingly, while digging up the URLs for this post, I noticed that VMware Server just went from Beta to GA Release acouple days ago... Now I'm off for another download.