Search engine optimization began in the early 1990s with the development of the first search engines like Archie and Gopher. In the mid-1990s, the first search engine robots were created, and Lycos, Yahoo, and Galaxy popularized the concept of search engines. Some companies began experimenting with search engine optimization techniques in 1994 by focusing on submission processes. However, spamming of search engines also emerged, leading to an ongoing "cat and mouse" game between optimizers and engines to manipulate or prevent manipulation of results. Black hat SEO techniques became common, though search engines adapted algorithms to curb spamming and provide better services to users.