How do I find out if my MacBook Pro supports virtual extensions? I am curious to know if it's possible to use my MacBook Pro as virtual host to test application in different OS environments. I guess it would improve performance of applications running on virtual OS .
Yes, All recent Macs support virtualization.

Apple released native hypervisor functionality with their OS X Yosemite release, their Hypervisor.framework.

What this does is it allows you to run a VM natively on OS X, without the need for client hypervisor (such as VMware Fusion or VirtualBox).

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