In 1990 the company released Stacker, a disk compression utility. The product was highly successful, due to the relatively small capacities (20 to 80 megabytes) and high prices of contemporary hard drives, at a time when larger software packages such as Microsoft's new Windows user interface were becoming popular. On average, Stacker doubled disk capacity, and usually increased disk performance by compressing the data before writing and after reading, compensating for the relative slowness of the drives. Stac sold several million units of Stacker over the product's lifetime.
