Systems programming (or system programming) is the activity of programming system software. The primary distinctive characteristic of systems programming when compared to application programming is that systems programming requires a greater degree of hardware awareness. More specifically: Computer programming (often simply programming) is the craft of implementing one or more interrelated abstract algorithms using a particular programming language to produce a concrete computer program. ... System software is a generic term referring to any computer software whose purpose is to help run the computer system. ... Computer programming (often simply programming) is the craft of implementing one or more interrelated abstract algorithms using a particular programming language to produce a concrete computer program. ...

• the programmer will make assumptions about the hardware and other machine architecture properties of the system that the program runs on, and will often exploit those properties (for example by using an algorithm that is known to be efficient when used with specific hardware);

• usually a low-level programming language or programming language dialect is used that:
  • can operate in resource-constrained environments;
  • is very efficient and has little runtime overhead;
  • has a small runtime library, or none at all;
  • allows for direct and "raw" control over memory access and control flow;
  • lets the programmer write parts of the program directly in assembly language;

• debugging is often very hard when it is not possible to run the program in a debugger due to resource constraints (running the program in a simulated environment can help here);

Systems programming is sufficiently different from application programming that programmers tend to specialize in one or the other. In computer science, runtime describes the operation of a computer program, the duration of its execution, from beginning to termination (compare compile time). ... In computer science, runtime describes the operation of a computer program, the duration of its execution, from beginning to termination (compare compile time). ... In computer science and in computer programming, statements in pseudocode or in a program are normally obeyed (or executed) one after the other in the order in which they are written (sequential flow of control). ... Assembly language or simply assembly is a human-readable notation for the machine language that a specific computer architecture uses. ... Debugging is a methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware thus making it behave as expected. ... A computer simulation or a computer model is a computer program which attempts to simulate an abstract model of a particular system. ...

In system programming, often limited programming facilities are available. The use of automatic garbage collection is not common and debugging is sometimes hard to do. The runtime library, if available at all, is usually far less powerful, and does less error checking. Because of those limitations, monitoring and logging are often used; operating systems may have extremely elaborate logging subsystems. In computing, garbage collection (also known as GC) is a form of automatic memory management. ... Debugging is a methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware thus making it behave as expected. ... In computer science, runtime describes the operation of a computer program, the duration of its execution, from beginning to termination (compare compile time). ... Data logging is the practice of recording, in some medium, sequential input, often in a time-associated format. ...

Originally systems programmers invariably wrote in assembly language. Experiments with hardware support in high-level languages in the late 1960s led to such languages as BLISS and BCPL, but C, helped along by the growth of UNIX, became ubiquitous in the 1980s. More recently C++ has seen some use, for instance in the IOKit drivers of Mac OS X. The 1960s, or The Sixties, in its most obvious sense refers to the decade between 1960 and 1969, but the expression has taken on a wider meaning over the past twenty years. ... BLISS is a system programming language developed at Carnegie-Mellon by W. A. Wulf, D. B. Russell, and A. N. Habermann around 1970. ... BCPL (Basic Combined Programming Language) is a computer programming language that was designed by Martin Richards of the University of Cambridge in 1966; it was originally intended for use in writing compilers for other languages. ... The C Programming Language, Brian Kernighan and Dennis Ritchie, the original edition that served for many years as an informal specification of the language The C programming language is a standardized programming language developed in the early 1970s by Ken Thompson and Dennis Ritchie for use on the UNIX operating... Unix or UNIX is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T Bell Labs employees including Ken Thompson, Dennis Ritchie, and Douglas McIlroy. ... // Events and trends The 1980s marked an abrupt shift towards more conservative lifestyles after the momentous cultural revolutions which took place in the 1960s and 1970s and the definition of the AIDS virus in 1981. ... C++ (pronounced see plus plus) is a general-purpose computer programming language. ... Mac OS X is the latest version of the Mac OS, the operating system software for Macintosh computers. ...