That's not a bad link, except that it calls "ka mate" THE Maaori haka. It is a haka, one of a great many, and by no means the best, imo. The composing and performing of haka is now an organised sport in NZ, called kapa haka, and some of the compositions, especially from areas where Maaori is still the first language, can be quite inspiring. Not surprisingly, the NZ Maori rugby team has its own specially-written haka, which knocks "ka mate" into a cocked hat.