The IBM 360 series of computers (System/360) was one of the first families of computers. The plan was to provide a wide range of computers, in price and performance, which were compatible with one another in what was termed "upward compatibility." This meant that programs written on lower priced, less powerful models could be run on the more expensive, more powerful models. Customers could, for the first time, upgrade the power of their computing systems without having to rewrite programs for a new system. The concept proved extremely popular and was adopted by other computer manufacturers of the mid- 1960s. Upward compatibility remains an industry standard.