The vmxnet and vmxnet3 networking drivers improve network performance. Which driver is used depends on how you configure device settings for the virtual machine. Search the VMware Knowledge Base for information on which guest operating systems support these drivers. The host-guest file system module, called hgfs.sys on Windows guests and vmhgfs on Linux and Solaris, is required to use the virtual machine with Workstation or Fusion and share folders between hosts and guests. The Virtual Machine Communication Interface driver allows fast and efficient communication between virtual machines. Developers can write client-server applications to the VMCI Sock (vsock) interface to make use of the VMCI virtual device.