Typically, the diskettes containing the software programs are inside a sealed package and the license is printed on the package. The license claims that a buyer's opening of the package is effective as acceptance to the license terms. The software is shareware. With shareware, copying software and sharing it with others is not only permitted, it's encouraged. Users may evaluate shareware software and then pay a registration fee to the author if they wish to continue using the software and receive manuals, technical support, and program updates.
Users can also copy and distribute public domain software.
Unlike shareware, public domain software lacks a registration fee. The Copyright Act allows users to make a copy of copyrighted software for backup purposes if a backup copy is not provided. For several years, industry analysts have estimated that for every legitimate program purchased there are between two and ten illegitimate copies made. The potential economic impact of unauthorized copying on the software industry is considerable. Software publishers use various strategies besides laws and agreements in attempt to stop theft of their products.