Encyclopedia of Computer Science and Technology

systems programming 465network facilities, program language compilers and othersoftware development tools, utilities, and device drivers.However, systems programmers can also work for applicationsdevelopers to help them interface their programs tothe operating system or to devices (see device driver andapplications programming interface).Modern operating systems are highly complex, so systemsprogrammers tend to specialize in particular areas.These might include device drivers, software developmenttools, program language libraries, applications programminginterfaces (APIs), and utilities for monitoring systemconditions and resources. Systems programmers developthe infrastructure needed for networking, as well as multiple-processorcomputers and distributed computing systems.Systems programmers also play a key role when anapplication program must be “ported” to a different platformor simply modified to run under a new version of theoperating system.Generally, an application programmer works at a fairlyhigh level, using language functions and APIs to have theprogram ask the operating system for services such as loadingor saving files, printing, and so on. The systems programmer,on the other hand, must be concerned with theinternal architecture of the system (such as the buffers allocatedto hold various kinds of temporary data) and withhow commands are constructed for disks and other devices.Generally, the systems programmer must also have a morethorough knowledge of data structures and how they arephysically represented in the machine as well as the comparativeefficiency of various algorithms. Because it determineshow efficiently the system’s resources can be used,systems programming must often be “tight” and optimizedfor peak performance. Thus, although lower-level assemblylanguage is no longer used for much applications programming,it can still be found in systems programming.Further ReadingBeck, Leland L. System Software: An Introduction to Systems Programming.3rd ed. Reading, Mass.: Addison-Wesley, 1996.Hart, Johnson M. Windows System Programming. 3rd ed. UpperSaddle River, N.J.: Addison-Wesley Professional, 2004.Love, Robert. Linux System Programming. Sebastapol, Calif.:O’Reilly Media, 2007.Robbins, Kay A., and Steven Robbins. UNIX Systems Programming.Upper Saddle River, N.J.: Prentice Hall PTR, 2003.