That was an artist-run, pre-web bulletin board system that became an early-web ISP provider and general host for artist-enabled projects. It was built and run by an artist named Wolfgang Staehle, who was directly grounded in a New York and international conceptual art framework.
Kevin McCoy, Kevin McCoy on Bridging net.art and Blockchain
At that time, there was another organization that was even more important than Rhizome and that was the Thing.
Kevin McCoy, Kevin McCoy on Bridging net.art and Blockchain