The Open Virtual Machine Tools (open-vm-tools) are
an open source implementation of VMware Tools.
They are a set of guest operating system
virtualization components that enhance the
performance and user experience of virtual
machines. The tools are currently composed of
kernel modules for Linux and user-space programs
for all VMware supported Unix-like guest operating
systems. They provide several useful functions
like file transfer between a host and guest,
improved memory management and network performance
under virtualization, and general mechanisms and
protocols for communication between host and
guests and from guest to guest.