The Boards of Canada group hosted on Yahoo! Groups is a prominant BoC forums and one of oldest continously active BoC groups, dating back to 2000.
The original group, boardsofcanada, was founded by bibowski on May 17, 2000.
As time went on, mailing list spam became a larger and larger problem. With the group moderator inactive, there wasn't anyway to stop spam from getting to the list. In reponse to this, a new group, boards-of-canada, was formed on April 10, 2004 by bplotkin. While the previous group still exists, most discussion now occurs on this group.