DALnet was formed in July 1994 to break away from the chaos there was at the time on EFnet with takeovers, netsplits and unstability. DALnet decided early on to go for userservices, and was one of the first networks who introduced nickserv.

A complete writeup on DALnets history can be found here:

Underworld is linked to the network with the servername underworld.se.eu.dal.net and uworld.hub.dal.net