However, there are specific digital newsstands for pornographic magazines. Software such as Apple's discontinued Newsstand enabled the downloading and displaying of digital versions of magazines, but did not allow pornographic material. With the continued progression of print media to digital, retailers have also had to adapt. Magazines may also carry articles on topics including cars, humor, science, computers, culture and politics. Well-known adult magazines include Playboy, Penthouse, Playgirl and Hustler. Examples include Asian Babes which focuses on Asian women, or Leg Show which concentrates on women's legs. Some magazines are general in their content, while others may be more specific and focus on a particular pornographic niche, part of the anatomy, or model characteristics. They primarily serve to stimulate sexual arousal, and are often used as an aid to masturbation. Publications of this kind may contain images of attractive naked subjects, as is the case in softcore pornography, and, in the usual case of hardcore pornography, depictions of masturbation, oral, vaginal or anal sex. Pornographic magazines or erotic magazines, sometimes known as adult, sex or top-shelf magazines, are magazines that contain content of an explicitly sexual nature. Pornographic magazines on display in a Japanese shop, 2009
