WHC started in Early September 1999 with TFC. Counter-strike became big on Wireplay around October-November (First beta of CS was Late June 1999 - Second around September). ZERO started around December 1999 as I remember Tolerance (Carnage) and Respect creating the clan about the time WHC started playing CS.
WHC and Zero would have to be 2 of the longest running clans. Mainly because we don't take it too seriously.
Been a lot of fun! The fact that I still haven't met a large portion of WHC and Zero is suprising after nearly 4 years
But definiately have some great friendships, even with members who don't actively play anymore.