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/