|
A computing platform is, in the most general sense, whatever pre-existing environment a piece of computer software or code object is designed to run within, obeying its constraints, and making use of its facilities. The term ''computing platform'' can refer to different abstraction levels, including a certain hardware architecture, an operating system (OS), and runtime libraries.〔Free Online Dictionary of Computing〕 In total it can be said as stage on which computer programs can run. Binary executables have to be compiled for a specific hardware platform, since different central processor units have different machine codes. In addition, operating systems and runtime libraries allow re-use of code and provide abstraction layers which allow the same high-level source code to run on differently configured hardware. For example, there are many kinds of data storage device, and any individual computer can have a different configuration of storage devices; but the application is able to call a generic save or write function provided by the OS and runtime libraries, which then handle the details themselves. A platform can be seen both as a constraint on the application development process – the application is written ''for'' such-and-such a platform – and an assistance to the development process, in that they provide low-level functionality ready-made.==Components== Platforms may also include: * Hardware alone, in the case of small embedded systems. Embedded systems can access hardware directly, without an OS. * A browser in the case of web-based software. The browser itself runs on a hardware+OS platform, but this is not relevant to software running within the browser.〔(Information Week )〕 * An application, such as a spreadsheet or word processor, which hosts software written in an application-specific scripting language, such as an Excel macro. This can be extended to writing fully-fledged applications with the Microsoft Office suite as a platform.〔(Microsoft )〕 * Software frameworks that provide ready-made functionality. * Cloud computing and Platform as a Service. Extending the idea of a software framework, these allow application developers to build software out of components that are hosted not by the developer, but by the provider, with internet communication linking them together.〔(Interoute )〕 The social networking sites Twitter and facebook are also considered development platforms.〔(Twitter )〕〔(Facebook )〕 * A virtual machine (VM) such as the Java virtual machine.〔(Oracle )〕 Applications are compiled into a format similar to machine code, known as bytecode, which is then executed by the VM. * A virtualized version of a complete system, including virtualized hardware, OS, software and storage. These allow, for instance, a typical Windows program to run on what is physically a Mac. Some architectures have multiple layers, with each layer acting as a platform to the one above it. In general, a component only has to be adapted to the layer immediately beneath it. For instance, a java program has to be written to use the java virtual machine (JVM) and associated libraries as a platform, but does not have to be adapted to run for the Windows, Linux or Macintosh OS platforms. However, the JVM, the layer beneath the application, does have to be built separately for each OS.〔(Stack Overflow )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Computing platform」の詳細全文を読む スポンサード リンク
|