In the past, I've used Maxivista to use a laptop's screen as an additional monitor for my primary computer. It works great, and I'm quite pleased with it.
However, I've now upgraded to Windows 8, and Maxivista doesn't support that version of Windows. I've done some searching and have not been able to find any utility like Maxivista that supports Windows 8. The only Maxivista-like utility I've found is "Zonescreen," which also does not support Windows 8. Does such a utility exist for Windows 8?
Note that I am not talking about desktop mirroring or a software KVM. I've found apps like VNC and Synergy that allow you to do those things, but I'm looking to extend my desktop.
I've searched here on Superuser.com and I see quite a few questions about this, all related to Windows 7 and earlier.