IBM is strangely enough completely absent from the Japanese part of the TOP500 in spite of its long presence in the Japanese market and its installed base of several hundreds IBM/3090 or ES/9000 systems. As opposed to its efforts in Europe IBM have not in Japan had an equivalent to the EASI programme which ensured vector processor installations in many European installations.
Thinking Machine Corporation is the other American supercomputer company (in addition to Cray) that has had the best penetration in Japan's TOP500. Eight installations are represented, mainly in the academic community and beyond the end of this list there are also some smaller systems.
Kendall Square Research is present in Japan with two systems acquired by Canon's Supercomputer Division which grew out of the acquisition of the Japanese Floating Point System (FPS) subsidiary some years ago. One of the two systems has been sold to the Advanced Telecommunications Research Institute (ATR) and the other one is kept by Canon for benchmarking and system tests. Canon also markets Cray computers and operate a dual processor Y-MP/4E for the same purposes.
nCube Corporation is present in Mitsubishi Electric with an nCube/2 with 512 processors. There are several other smaller nCube systems in Japan, including one in ATR (whose usage is discussed later on). Large Intel systems have been acquired by the Real World Computing Project and by Hiroshima University and similarly to TMC there are also several smaller systems installed.