UnrealIRCd is an IRC server based on the branch of IRCu called Dreamforge,

UnrealIRCd is an IRC server based on the branch of IRCu called Dreamforge,
formerly used by the DALnet IRC Network. Since development started on it
(around May 1999) many new features has been added, modified, and many bugs
fixed. Unreal runs both on *nix platforms, Amiga & Windows 95/98/2k/NT.
Some features to mention: Channel Halfops, No-color channel mode,
Strip-colors channel mode, channelmode +q & +a - protect modes, Oper and
Admin only channels, exception bans, Nokicks mode (channel and user), Flood
limiter, Channel links, Host cloaking, Net* Tech and Co-Admin modes, Whois
notifies, Foreign connects monitor, Oper suspend, G:Lines, T:Lines, channel
restriction (people can only go to these channels if enabled), Trojan/DCC
Deny, RPING/RPONG, Sethost family, Token in server<->server etc.
FDlists/High Traffic Mode, SOCKS check on connect, Speeded up server
synchs, limited WebTV Client support, /vhost, and many dreamforge
optimations. UnrealIRCd is aimed to be an advanced, not an easy IRCd.

Also includes SSL and IPv6 support.