[Hampshire] what is BBC iplayer video playback - flash?

What is the inside story of bbc iplayer playback?

Is it flash?

What is known about its playback processes? I can record broadcast tv
with conventional recorders, and capture streaming flash from google
or utube fairly easily, but bbc iplayer stuff does not seem to be
shown in (firefox) cache nor does it seem to be available to capture.
It would sometimes be convenient to capture it. A belt and braces
method I know works is to use something like recordmydesktop, but it
is not very elegant as a method.
--
alan cocks
Kubuntu user#10391
Linux user #360648