It is always easy to concentrate on MIPS and Flop/s (as indeed we do in this list), but it should always be remembered that the satisfactory use of supercomputers as effective tools is mostly dependent on a sophisticated software environment for application development and execution. To this extent, the Japanese users have been forced to look beyond the domestic suppliers to the American ones, such as Cray and TMC, for a well-established application portfolio founded on a solid operating system basis and surrounded by mature library implementations, debuggers, profilers, and visualisation software. The ease of portability created by the adoption of Unix as a base should slowly make the playground more even, but so far, Cray and other American companies have maintained a solid lead over the Japanese counterparts. In order to correct the situation NEC, Fujitsu and Hitachi have established competence centres and collaborations in the United States. Collaborations with European and Australian sites, installing Japanese hardware, is commonly based on agreements of software development for the application areas that correspond to the customer concerned. In certain cases there may be political pressure to stop applications being ported to Japanese platforms. This is the case today with PAM- crash which is a vital applications package for automobile crash simulation and certification.