I couldn't explain it better than they do!

[wiki, abbreviation of ))WikiWikiWeb, name given in 1995 by American computer programmer Ward Cunningham to his new code, which permits the easy development of collaborative websites whose content can be edited by anyone with access to them. From Hawaiian wikiwiki “fast, speedy,??? reduplication of wiki “fast,??? akin to Tahitian viti and vitiviti, “deft, alert, well done,??? both fromProto-Eastern-Polynesian(( *witi.]

Patrick adds, You’ve probably noticed that the Hawaiian word has a k where the Tahitian has a t. This is a regular correspondence between Hawaiian and the other Austronesian languages. Other examples include Hawaiian maka “eye??? and koko “blood,??? which correspond to Tahitian mata “eye,??? toto “blood,??? and to Samoan mata, toto too. The same correspondence shows up in Hawaiian kapu “sacred, forbidden??? next to Maori, Rarotongan, Samoan, and Tahitian tapu. One of these (we are not quite certain which) was the source of our English word taboo. Of course, we can't forget that "aloha" in Samoan is "talofa".