A software component is a modular unit of software that encapsulates specific functionality. [1] The desired characteristics of a component are reusability and maintainability. [1]
Components allow software development to assemble software with reliable parts rather than writing code for every aspect; allowing for implementation to be more like factory assembly than custom building.
Desirable attributes of a component include but are not limited to:
Some components are built in-house by the same organization or team building the software system. Some are third-party, developed elsewhere and assembled into the software system. [2]
For large-scale systems, component-based development encourages a disciplined process to manage complexity. [3]
Some components conform to a framework technology that allows them to be consumed in a well-known way. Examples include: CORBA, COM, Enterprise JavaBeans, and the .NET Framework. [4] [5]
Component design is often modeled visually. In Unified Modeling Language (UML) 2.0 a component is shown as a rectangle, and an interface is shown as a lollipop to indicate a provided interface and as a socket to indicate consumption of an interface.
The idea of reusable software components was promoted by Douglas McIlroy in his presentation at the NATO Software Engineering Conference of 1968. [6] (One goal of that conference was to resolve the so-called software crisis of the time.) In the 1970s, McIlroy put this idea into practice with the addition of the pipeline feature to the Unix operating system.
Brad Cox refined the concept of a software component in the 1980s. [7] He attempted to create an infrastructure and market for reusable third-party components by inventing the Objective-C programming language. [8]
IBM introduced System Object Model (SOM) in the early 1990s. [9]
Microsoft introduced Component Object Model (COM) in the early 1990s. Microsoft built many domain-specific component technologies on COM, including Distributed Component Object Model (DCOM), Object Linking and Embedding (OLE), and ActiveX.
Software architecture is the set of structures needed to reason about a software system and the discipline of creating such structures and systems. Each structure comprises software elements, relations among them, and properties of both elements and relations.
ActiveX is a deprecated software framework created by Microsoft that adapts its earlier Component Object Model (COM) and Object Linking and Embedding (OLE) technologies for content downloaded from a network, particularly from the World Wide Web. Microsoft introduced ActiveX in 1996. In principle, ActiveX is not dependent on Microsoft Windows operating systems, but in practice, most ActiveX controls only run on Windows. Most also require the client to be running on an x86-based computer because ActiveX controls contain compiled code.
In computer science, a library is a collection of read-only resources that is leveraged during software development to implement a computer program.
In software engineering, a design pattern describes a relatively small, well-defined aspect of a computer program in terms of how to write the code.
OpenDoc is a defunct multi-platform software componentry framework standard created by Apple in the 1990s for compound documents, intended as an alternative to Microsoft's proprietary Object Linking and Embedding (OLE). It is one of Apple's earliest experiments with open standards and collaborative development methods with other companies. OpenDoc development was transferred to the non-profit Component Integration Laboratories, Inc., owned by a growing team of major corporate backers and effectively starting an industry consortium. In 1992, the AIM alliance was launched by Apple, IBM, and Motorola, with OpenDoc as a foundation. With the return of Steve Jobs to Apple, OpenDoc was discontinued in March 1997.
An object-oriented operating system is an operating system that is designed, structured, and operated using object-oriented programming principles.
The Law of Demeter (LoD) or principle of least knowledge is a design guideline for developing software, particularly object-oriented programs. In its general form, the LoD is a specific case of loose coupling. The guideline was proposed by Ian Holland at Northeastern University towards the end of 1987, and the following three recommendations serve as a succinct summary:
In software engineering, service-oriented architecture (SOA) is an architectural style that focuses on discrete services instead of a monolithic design. SOA is a good choice for system integration. By consequence, it is also applied in the field of software design where services are provided to the other components by application components, through a communication protocol over a network. A service is a discrete unit of functionality that can be accessed remotely and acted upon and updated independently, such as retrieving a credit card statement online. SOA is also intended to be independent of vendors, products and technologies.
Open Platform Communications (OPC) is a series of standards and specifications for industrial telecommunication. They are based on Object Linking and Embedding (OLE) for process control. An industrial automation task force developed the original standard in 1996 under the name OLE for Process Control. OPC specifies the communication of real-time plant data between control devices from different manufacturers.
In software development, code reuse, also called software reuse, is the use of existing software, or software knowledge, to build new software, following the reusability principles.
In the context of software engineering, software quality refers to two related but distinct notions:
ADO.NET is a data access technology from the Microsoft .NET Framework that provides communication between relational and non-relational systems through a common set of components. ADO.NET is a set of computer software components that programmers can use to access data and data services from a database. It is a part of the base class library that is included with the Microsoft .NET Framework. It is commonly used by programmers to access and modify data stored in relational database systems, though it can also access data in non-relational data sources. ADO.NET is sometimes considered an evolution of ActiveX Data Objects (ADO) technology, but was changed so extensively that it can be considered an entirely new product.
Architecture description languages (ADLs) are used in several disciplines: system engineering, software engineering, and enterprise modelling and engineering.
A software factory is a structured collection of related software assets that aids in producing computer software applications or software components according to specific, externally defined end-user requirements through an assembly process. A software factory applies manufacturing techniques and principles to software development to mimic the benefits of traditional manufacturing. Software factories are generally involved with outsourced software creation.
.NET Remoting is a Microsoft application programming interface (API) for interprocess communication released in 2002 with the 1.0 version of .NET Framework. It is one in a series of Microsoft technologies that began in 1990 with the first version of Object Linking and Embedding (OLE) for 16-bit Windows. Intermediate steps in the development of these technologies were Component Object Model (COM) released in 1993 and updated in 1995 as COM-95, Distributed Component Object Model (DCOM), released in 1997, and COM+ with its Microsoft Transaction Server (MTS), released in 2000. It is now superseded by Windows Communication Foundation (WCF), which is part of the .NET Framework 3.0.
Douglas Taylor "Doug" Ross was an American computer scientist pioneer, and chairman of SofTech, Inc. He is most famous for originating the term CAD for computer-aided design, and is considered to be the father of Automatically Programmed Tools (APT), a programming language to drive numerical control in manufacturing. His later work focused on a pseudophilosophy he developed and named Plex.
Apache Axis2 is a web service engine. It is a redesign and re-write of the widely used Apache Axis SOAP stack. Implementations of Axis2 are available in Java and C.
A view model or viewpoints framework in systems engineering, software engineering, and enterprise engineering is a framework which defines a coherent set of views to be used in the construction of a system architecture, software architecture, or enterprise architecture. A view is a representation of the whole system from the perspective of a related set of concerns.
T.H. Tse is a Hong Kong academic who is a professor and researcher in program testing and debugging. He is ranked internationally as the second most prolific author in metamorphic testing. According to Bruel et al., "Research on integrated formal and informal techniques can trace its roots to the work of T.H. Tse in the mid-eighties." The application areas of his research include object-oriented software, services computing, pervasive computing, concurrent systems, imaging software, and numerical programs. In addition, he creates graphic designs for non-government organizations.
Software intelligence is insight into the inner workings and structural condition of software assets produced by software designed to analyze database structure, software framework and source code to better understand and control complex software systems in information technology environments. Similarly to business intelligence (BI), software intelligence is produced by a set of software tools and techniques for the mining of data and the software's inner-structure. Results are automatically produced and feed a knowledge base containing technical documentation and blueprints of the innerworking of applications, and make it available to all to be used by business and software stakeholders to make informed decisions, measure the efficiency of software development organizations, communicate about the software health, prevent software catastrophes.
The modern concept of a software component largely defined by Brad Cox of Stepstone, => Objective-C programming language
1990, IBM invents their System Object Model. 1990, as a reaction, Microsoft released OLE 1.0 OLE custom controls (OCX)[ permanent dead link ]