COWS. Who love They Might Be Giants.
Every Wednesday, 5:00 PM Pacific/8:00 Eastern
IRC. The network is irc.rizon.net. Pidgin for Windows and Adium for Mac are two clients that can be used for both IRC and other chat protocols. Xchat Aqua/Azure for Mac and Hexchat for Windows and Linux are good dedicated IRC clients. Or if you prefer you can use the embedded client at the bottom of this page.
Because They Might Be Giants.
Now brown cow. Just open your client, say you want to join a chat, and type in "#cowtown."
Cowtown was started in fall of 1994. It originally existed only on AOL but when AIM became usable by other people it opened up to everyone. It closed down for awhile in the mid-2000's but was revived by Quinn on April 14, 2010. It made the move to IRC in 2017.