1) Virtual learning environment 
Ultranet can refer to one of the following: ...[product] The Ultranet was an online learning management system developed for the Victorian Department of Education and Early Childhood Development in Australia to provide extensive services to students, parents and teachers in government schools. The Ultranet was built by Australian IT firm CSG and phased into school use between 2006 and 2...
a net in a topological space that is residually in every set or its complement in the space.