A virtual appliance, "computer emulator", makes it possible to
run legacy software on modern and future hardware.
The Virtual appliance can be seen as a container that
includes a distributable application with
all of the right versions of its dependencies.

As of 2016 the format of the x86 and the AMD64
line of virtual appliances has been standardized and
is supported by multiple vendors.
In 2016 the recommended tool for running
x86 and AMD64 virtual appliances is the VirtualBox.

Please use BitTorrent, because
that allows the download to be paused and
continued at some later moment and
by using the BitTorrent the hash sum
of the downloaded file gets automatically verified.