Forgive me if I use any of these terms incorrectly.

I am wondering if there is any kind of software that would allow my two "join" two computers together such that a cluster unaware application could utilize their combined computing resources? By "cluster unaware" I mean an application that isn't designed to share work across multiple services. My understanding is that clustering is enabled by the specific application by it's architecture, such that messaging with multiple instances of the application coordinate the sharing of work. Instead I am looking for something that enables clustering at the OS or virtualization level, so that any application could essentially be clustered.

Failing that, I am also wondering about the following scenario: We have 3 different applications we will call A, B, and C. We have 2 single core computers. At any given time lets say that any combination of those applications will be CPU intensive. In cases where only 2 of those apps are very active, have one of them moved over to a different server. In a nutshell, some sort of dynamic automatic shuffling of the application's load.

I have heard of virtual machines that can be migrated across physical machines while live, but I am wondering if this can be done automatically in response to an application's or VM's CPU activity?