platform

A hardware and/or software architecture that serves as a foundation or base. The term originally dealt with only hardware, and it still refers to a CPU model or computer family. For example, the x86 PC is the world's largest hardware platform. IBM's iSeries (AS/400) and Sun's SPARC are also hardware platforms (see hardware platforms for a larger list). The terms "platform" and "environment" are used interchangeably. See environment.

An Operating System Platform
The term often refers to an operating system, and the hardware is generally implied. For example, when an application is said to "run on the Windows platform," it means that the program has been compiled into the x86 machine language and runs under Windows. It implies x86 because Windows runs mostly on x86 PCs.

The Xbox "gaming platform" refers to the Xbox proprietary operating system, but different hardware depending on model (Xbox or Xbox 360). The same goes for the "Palm platform," which ran the Palm OS on Motorola 68000 chips and later on ARM chips.

With Unix, the hardware may not be implied. The phrase "the program runs on the Unix platform" does not indicate which CPU family that particular program was compiled for. Unix programs run on almost every hardware platform, but they have to be compiled into the machine language of the hardware. See Unix.

Software Only - A Two Way Street
Operating systems are always "software platforms" because applications must interface with them. An application can also be a platform if it is a base for other programs. For example, Web browsers accept third-party plug-ins, which are small software components that add functionality. The browser becomes a platform to contain those components. A messaging or groupware platform is a base program that e-mail, calendaring and other client programs communicate with. Software platforms are always a two-way street; they provide the base functionality and communicate back and forth with other software.

A single application that runs in isolation is not a platform. For example, a simple photo editor that does not accept third-party plug-ins cannot be called a platform.

---

platform - Specific computer hardware, as in the phrase "platform-independent". It may also refer to a specific combination of hardware and operating system and/or compiler, as in "this program has been ported to several platforms". It is also used to refer to support software for a particular activity, as in "This program provides a platform for research into routing protocols".