ThinkPad is a line of laptop computers and tablets by Lenovo. The series was originally designed, developed, and sold by IBM until Lenovo acquired the brand in 2005 after purchasing IBM's personal computer business. ThinkPads are known for their minimalist, black design which was initially modeled in 1990 by industrial designer Richard Sapper based on the concept of a traditional Japanese Bento lunchbox revealing its nature only after being opened. According to later interviews with Sapper, he also characterized the simple ThinkPad form to be as elementary as a simple, black cigar box and with similar proportions that offers a 'surprise' when opened. ThinkPads are popular with large businesses and schools. Older ThinkPad models are revered by technology enthusiasts, collectors and power users due to their durable design, relatively high resale value, and abundance of aftermarket replacement parts. ThinkPad laptops have been used in space, and was by 2003 the only laptop certified for use on the International Space Station.