Can you run Hyper-V and VirtualBox at the same time?

The challenge is that VirtualBox and Hyper-V cannot co-exist on the same machine. Only one hypervisor can run at a time, and since Hyper-V runs all the time, while VirtualBox only runs when it is launched, VirtualBox is the loser in this scenario.

Can I run two virtual machines at once?

Yes you can run multiple virtual machines at once. They can appear as separate windowed applications or take over the full screen.

How do I setup a network between VirtualBox and VMware virtual machines?

Create a networking interface with bridged adapter on Virtualbox and map it to 1 of the physical adapters. Create a networking interface with bridged adapter on VMWare player and map it to the same physical adapter as Virtualbox. In this option, the connection between the 2 hosts is established through external router.

How many VMs Can you run simultaneously within a VirtualBox?

As much as you allow it. If you have enough space, there is no limit to the VMs you can set. Running them simultanious is a matter of memory.

Can you run Hyper-V and VMware on same server?

VMware Workstation/Player can now run when Hyper-V is enabled. You no longer have to choose between running VMware Workstation and Windows features like WSL, Device Guard and Credential Guard. If you don’t use Hyper-V at all, VMware Workstation is smart enough to detect this and the VMM will be used.

How do I switch between Hyper-V and VirtualBox?

Now if you hold the shift key when restarting your windows you will have the option to boot into a windows with Hyper-V off and VirtualBox runs with no issues.

How do I connect two virtual machines to another host?

You just need to forward the ports that you want (which you can do in VirtualBox’s network settings), then connect to the IP of one host from the other host’s VM. As @TJJ said, your other option is to used bridged networking instead of NAT, which would let the computers connect with no extra configuration.