dmoz was founded in the united states as gnuhoo by rich skrenta and bob truel in 1998 while they were both working as engineers for sun microsystems. chris tolles, who worked at sun microsystems as the head of marketing for network security products, also signed on in 1998 as a co-founder of gnuhoo along with co-founders bryn dole and jeremy wenokur. skrenta had developed tass, an ancestor of tin, the popular threaded usenet newsreader for unix systems. the original category structure of the gnuhoo directory was based loosely on the structure of usenet newsgroups then in existence.