Today we have TPS (transparent page sharing) vmmenctl (ballooning) and esx hosts swapping. But a new technology is coming: Memory Compression
I am not allowed to say anything about this technology because of NDA, but Scott Drummonds has written an interesting article about the future feature memory compression. You can check out Scotts article: here
The good thing about this technology is that Vmware will be even better at overcommitting memory. Every customer/partner/student I ask the same question: “What is the limiting resource on your ESX hosts?” and almost everyone answers MEMORY.
This will give us the option to run more on less.