Window managerA window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment. They work in conjunction with the underlying graphical system that provides required functionality—support for graphics hardware, pointing devices, and a keyboard—and are often written and created using a widget toolkit. Few window managers are designed with a clear distinction between the windowing system and the window manager.
Tiling window managerIn computing, a tiling window manager is a window manager with an organization of the screen into mutually non-overlapping frames, as opposed to the more common approach (used by stacking window managers) of coordinate-based stacking of overlapping objects (windows) that tries to fully emulate the desktop metaphor. The first Xerox Star system (released in 1981) tiled application windows, but allowed dialogs and property windows to overlap. Later, Xerox PARC also developed CEDAR (released in 1982), the first windowing system using a tiled window manager.
Execution (computing)Execution in computer and software engineering is the process by which a computer or virtual machine reads and acts on the instructions of a computer program. Each instruction of a program is a description of a particular action which must be carried out, in order for a specific problem to be solved. Execution involves repeatedly following a 'fetch–decode–execute' cycle for each instruction done by control unit. As the executing machine follows the instructions, specific effects are produced in accordance with the semantics of those instructions.
X Window SystemThe X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting with a mouse and keyboard. X does not mandate the user interface - this is handled by individual programs. As such, the visual styling of X-based environments varies greatly; different programs may present radically different interfaces.
SimulationA simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the simulation represents the evolution of the model over time. Often, computers are used to execute the simulation. Simulation is used in many contexts, such as simulation of technology for performance tuning or optimizing, safety engineering, testing, training, education, and video games.
Search engine (computing)A search engine is an information retrieval system designed to help find information stored on a computer system. It is an information retrieval software program that discovers, crawls, transforms, and stores information for retrieval and presentation in response to user queries. The search results are usually presented in a list and are commonly called hits. A search engine normally consists of four components, as follows: a search interface, a crawler (also known as a spider or bot), an indexer, and a database.
Enterprise searchEnterprise search is the practice of making content from multiple enterprise-type sources, such as databases and intranets, searchable to a defined audience. "Enterprise search" is used to describe the software of search information within an enterprise (though the search function and its results may still be public). Enterprise search can be contrasted with web search, which applies search technology to documents on the open web, and desktop search, which applies search technology to the content on a single computer.
Constraint satisfaction problemConstraint satisfaction problems (CSPs) are mathematical questions defined as a set of objects whose state must satisfy a number of constraints or limitations. CSPs represent the entities in a problem as a homogeneous collection of finite constraints over variables, which is solved by constraint satisfaction methods. CSPs are the subject of research in both artificial intelligence and operations research, since the regularity in their formulation provides a common basis to analyze and solve problems of many seemingly unrelated families.
Nurse scheduling problemThe nurse scheduling problem (NSP), also called the nurse rostering problem (NRP), is the operations research problem of finding an optimal way to assign nurses to shifts, typically with a set of hard constraints which all valid solutions must follow, and a set of soft constraints which define the relative quality of valid solutions. Solutions to the nurse scheduling problem can be applied to constrained scheduling problems in other fields. The nurse scheduling problem has been studied since before 1969, and is known to have NP-hard complexity.
Windowing systemIn computing, a windowing system (or window system) is a software suite that manages separately different parts of display screens. It is a type of graphical user interface (GUI) which implements the WIMP (windows, icons, menus, pointer) paradigm for a user interface. Each currently running application is assigned a usually resizable and usually rectangular surface of the display to present its GUI to the user; these windows may overlap each other, as opposed to a tiling interface where they are not allowed to overlap.
Widget toolkitA widget toolkit, widget library, GUI toolkit, or UX library is a library or a collection of libraries containing a set of graphical control elements (called widgets) used to construct the graphical user interface (GUI) of programs. Most widget toolkits additionally include their own rendering engine. This engine can be specific to a certain operating system or windowing system or contain back-ends to interface with more multiple ones and also with rendering APIs such as OpenGL, OpenVG, or EGL.
Scheduling (computing)In computing, scheduling is the action of assigning resources to perform tasks. The resources may be processors, network links or expansion cards. The tasks may be threads, processes or data flows. The scheduling activity is carried out by a process called scheduler. Schedulers are often designed so as to keep all computer resources busy (as in load balancing), allow multiple users to share system resources effectively, or to achieve a target quality-of-service.
