This category contains sites of companies that either sell supercomputers or sell time on supercomputers. While there are many types of computers that can be classified as supercomputers, this category is for the sale of the specific sort of supercomputer that is sold as one unit (if the product can be classified as a 'cluster', it's a parallel computer, not a supercomputer) and is not manufactured from commodity hardware (that's a Beowulf).
Conferences about parallel computing are listed in Computers/Parallel_Computing/Conferences. Conferences about distributed computing are listed in Computers/Computer_Science/Distributed_Computing/Conferences_and_Workshops. General computer science conferences are listed in Computers/Computer_Science/Conferences.This category contains sites about conferences about supercomputing.