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IDispatch
IDispatch is the interface that exposes the OLE Automation protocol. Extending IUnknown, it is one of the standard interfaces that can be exposed by COM objects. COM distinguishes between three interface types: ''custom'' that are VTABLE-based IUnknown interfaces, ''dispatch'' that are IDispatch interfaces supporting introspection, and ''dual'' interfaces supporting both types. The Automation (IDispatch) interface allows a client application to find out what properties and methods are supported by an object at run-time, i.e. implements the concept of RTTI. It also provides the information necessary to invoke these properties and methods. Client applications do not need to be aware of the object members when they are compiled. This allows COM and ActiveX objects to be called by scripting programs platforms such as the ASP server and JavaScript on Internet Explorer, where calling conventions were not known at the time IIS or IE were built. By contrast, a simple object library is ...
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OLE Automation
In Microsoft Windows applications programming, OLE Automation (later renamed to simply Automation) is an inter-process communication mechanism created by Microsoft. It is based on a subset of Component Object Model (COM) that was intended for use by scripting languages – originally Visual Basic – but now is used by several languages on Windows. All automation objects are required to implement the IDispatch interface. It provides an infrastructure whereby applications called ''automation controllers'' can access and manipulate (i.e. set properties of or call methods on) shared ''automation objects'' that are exported by other applications. It supersedes Dynamic Data Exchange (DDE), an older mechanism for applications to control one another. As with DDE, in OLE Automation the automation controller is the "client" and the application exporting the automation objects is the "server". Contrary to its name, automation objects do not necessarily use Microsoft OLE, although ...
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Late Binding
In computing, late binding or dynamic linkage—though not an identical process to dynamically linking imported code libraries—is a computer programming mechanism in which the method being called upon an object, or the function being called with arguments, is looked up by name at runtime. In other words, a name is associated with a particular operation or object at runtime, rather than during compilation. The name dynamic binding is sometimes used, but is more commonly used to refer to dynamic scope. With early binding, or static binding, in an object-oriented language, the compilation phase fixes all types of variables and expressions. This is usually stored in the compiled program as an offset in a virtual method table ("v-table"). In contrast, with late binding, the compiler does not read enough information to verify the method exists or bind its slot on the v-table. Instead, the method is looked up by name at runtime. The primary advantage of using late binding in ...
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IUnknown
In computer programming, the IUnknown interface is the fundamental interface in the Component Object Model (COM). The COM specification mandates that COM objects must implement this interface. Furthermore, every other COM interface must be derived from IUnknown. IUnknown exposes two essential features of all COM objects: object lifetime management through reference counting, and access to object functionality through other interfaces. An IUnknown (or IUnknown-derived) interface consists of a pointer to a virtual method table that contains a list of pointers to the functions that implement the functions declared in the interface, in the order that they are declared in the interface. The in-process invocation call overhead is therefore identical to virtual method calls in C++. Methods The IUnknown interface exposes three methods: QueryInterface, AddRef, and Release:
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Variant Type (COM)
Variant is a data type in certain programming languages, particularly Visual Basic, OCaml, Delphi and C++ when using the Component Object Model. It is an implementation of the eponymous concept in computer science. In Visual Basic (and Visual Basic for Applications) the Variant data type is a tagged union that can be used to represent any other data type (for example, integer, floating-point, single- and double-precision, object, etc.) except fixed-length string type. In Visual Basic, any variable not declared explicitly or the type of which is not declared explicitly, is taken to be a variant. While the use of not explicitly declared variants is not recommended, they can be of use when the needed data type can only be known at runtime, when the data type is expected to vary, or when optional parameters and parameter arrays are desired. In fact, languages with a dynamic type system often have variant as the ''only'' available type for variables. Among the major changes in ...
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Interface (computer Science)
In computing, an interface is a shared boundary across which two or more separate components of a computer system exchange information. The exchange can be between software, computer hardware, peripheral devices, humans, and combinations of these. Some computer hardware devices, such as a touchscreen, can both send and receive data through the interface, while others such as a mouse or microphone may only provide an interface to send data to a given system. Hardware interfaces Hardware interfaces exist in many components, such as the various buses, storage devices, other I/O devices, etc. A hardware interface is described by the mechanical, electrical, and logical signals at the interface and the protocol for sequencing them (sometimes called signaling). See also: A standard interface, such as SCSI, decouples the design and introduction of computing hardware, such as I/O devices, from the design and introduction of other components of a computing system, thereby allowin ...
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Open-source Model
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized software development model that encourages open collaboration. A main principle of open-source software development is peer production, with products such as source code, blueprints, and documentation freely available to the public. The open-source movement in software began as a response to the limitations of proprietary code. The model is used for projects such as in open-source appropriate technology, and open-source drug discovery. Open source promotes universal access via an open-source or free license to a product's design or blueprint, and universal redistribution of that design or blueprint. Before the phrase ''open source'' became widely adopted, developers and producers have used a variety of other terms. ''Open source'' gained ...
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Globally Unique Identifier
A universally unique identifier (UUID) is a 128-bit label used for information in computer systems. The term globally unique identifier (GUID) is also used. When generated according to the standard methods, UUIDs are, for practical purposes, unique. Their uniqueness does not depend on a central registration authority or coordination between the parties generating them, unlike most other numbering schemes. While the probability that a UUID will be duplicated is not zero, it is generally considered close enough to zero to be negligible. Thus, anyone can create a UUID and use it to identify something with near certainty that the identifier does not duplicate one that has already been, or will be, created to identify something else. Information labeled with UUIDs by independent parties can therefore be later combined into a single database or transmitted on the same channel, with a negligible probability of duplication. Adoption of UUIDs is widespread, with many computing platform ...
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String (computer Science)
In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable. The latter may allow its elements to be mutated and the length changed, or it may be fixed (after creation). A string is generally considered as a data type and is often implemented as an array data structure of bytes (or words) that stores a sequence of elements, typically characters, using some character encoding. ''String'' may also denote more general arrays or other sequence (or list) data types and structures. Depending on the programming language and precise data type used, a variable declared to be a string may either cause storage in memory to be statically allocated for a predetermined maximum length or employ dynamic allocation to allow it to hold a variable number of elements. When a string appears literally in source code, it is known as a string literal or an anonymous string. In formal languages, which are used in ma ...
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Internet Information Services
Internet Information Services (IIS-pronounced 2S, formerly Internet Information Server) is an extensible web server software created by Microsoft for use with the Windows NT family. IIS supports HTTP, HTTP/2, HTTPS, FTP, FTPS, SMTP and NNTP. It has been an integral part of the Windows NT family since Windows NT 4.0, though it may be absent from some editions (e.g. Windows XP Home edition), and is not active by default. History The first Microsoft web server was a research project at the European Microsoft Windows NT Academic Centre (EMWAC), part of the University of Edinburgh in Scotland, and was distributed as freeware. However, since the EMWAC server was unable to handle the volume of traffic going to Microsoft.com, Microsoft was forced to develop its own web server, IIS. Almost every version of IIS was released either alongside or with a version of Microsoft Windows: * IIS 1.0 was initially released as a free add-on for Windows NT 3.51. * IIS 2.0 was included with W ...
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Dynamic Data Exchange
In computing, Dynamic Data Exchange (DDE) is a technology for interprocess communication used in early versions of Microsoft Windows and OS/2. DDE allows programs to manipulate objects provided by other programs, and respond to user actions affecting those objects. DDE was partially superseded by Object Linking and Embedding (OLE), and is currently maintained in Windows systems only for the sake of backward compatibility. History and architecture Dynamic Data Exchange was first introduced in 1987 with the release of Windows 2.0 as a method of interprocess communication so that one program could communicate with or control another program, somewhat like Sun's RPC (Remote Procedure Call). At the time, the only method for communication between the operating system and client applications was the "Windows Messaging Layer." DDE extended this protocol to allow peer-to-peer communication among client applications, via message broadcasts. Because DDE runs via message broadcasts, ...
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Internet Explorer
Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical web browsers developed by Microsoft which was used in the Windows line of operating systems (in Windows 11, Windows Server Insider Build 22463 and Windows Server Insider Build 25110, it is replaced by the Chromium version of Microsoft Edge). Starting in 1995, It was first released as part of the add-on package Plus! for Windows 95 that year. Later versions were available as free downloads, or in- service packs, and included in the original equipment manufacturer (OEM) service releases of Windows 95 and later versions of Windows. Microsoft spent over per year on Internet Explorer in the late 1990s, with over 1,000 people involved in the project by 1999. New feature development for the browser was discontinued in 2016 in favor of new browser Microsoft Edge. Microsoft Teams ended support for IE on November 30, 2020, Microsoft 36 ...
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