A wide-area network
developed under the auspices of the National Science Foundation (NSF). NSFnet replaced ARPANET
as the main government network
linking universities and research facilities. In 1995, however, the NSF dismantled NSFnet and replaced it with a commercial Internet backbone. At the same time, the NSF implemented a new backbone called very high-speed Backbone Network Service (vBNS)
, which serves as a testing ground for the next generation of Internet technologies.