many large organization often hire their own programmers to write custom software. the Boeing company, for example, will not find software to plan the electrical wiring of an airplane among commercial packages. however, not all of a company's software need be custom-made. many companies use standard for standard tasks such as payroll and accounts receivable. furthermore, some software vendors specialize in a certain "vertical" slice of the business community, serving similar customers such as plumbers or accountants.