It should be noted that DALnet is, at the time of writing, effectively
dead. Sadly, they have been the victims of massive
DDoS attacks over the last 6 months, forcing countless
servers to
delink themselves from the network, and causing the remaining servers to
crash under the load of the attacks.
More information can be found at the DALnet web site www.dal.net.
Usage statistics showing the massive decline in DALnet users can be found at http://irc.netsplit.de/networks/DALnet/history.var
As an ex-DALnet user myself, it is very sad to see the death throes of a network I have enjoyed so much. However, I, and most other DALnet users have been forced to move to other networks such as EFnet, Undernet or Quakenet (amongst others), due to the unusable nature of the DALnet network. At the time of writing, user numbers are at 20% of their previous figures, with little hope of recovery, and the consensus among most users is that the network is dead for the forseeable future.
Quite simply, I can only hope this isn't the future of the internet, with massive DDoS attacks run by script kiddies off the machines of people who cannot be bothered to run a simple firewall or anti-virus.
Update: DALnet are planning a resurrection, however it has announced a shift in policy, banning channels dedicated to file sharing. Since that was (at least from my exposure) DALnet's primary use, its size is not likely to come even close to its previous levels, though only time will tell.