At least one of their supercomputers, the AP1000+,
runs GNU/Linux. This is a distributed memory multi-computer. It is used in the
CAP program which is a collaborative research program between
Fujitsu Laboratories and the
Australian National University.
This computer was used in the phase 1 of this
project.
They have managed to run Linux on a 16 node computer with 16 MB ram per CPU
module. More information about this project can be found on this page:
http://cap.anu.edu.au/cap/projects/linux/
More information can be found about Fujitsu's offering on this page: http://www.fujitsu.com/support/computing/server/unix/documents/