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A computing platform or digital platform  is an environment in which a piece of software is executed. It may be the hardware or the operating system (OS), even a web browser and associated application programming interfaces, or other underlying software, as long as the program code is executed with it. Computing platforms have different abstraction levels, including a computer architecture, an OS, or runtime libraries.  A computing platform is the stage on which computer programs can run.
A platform can be seen both as a constraint on the software development process, in that different platforms provide different functionality and restrictions; and as an assistant to the development process, in that they provide low-level functionality ready-made. For example, an OS may be a platform that abstracts the underlying differences in hardware and provides a generic command for saving files or accessing the network.
Platforms may also include:
- Hardware alone, in the case of small embedded systems. Embedded systems can access hardware directly, without an OS; this is referred to as running on " bare metal".
- 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. 
- 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. 
- 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.  The social networking sites Twitter and Facebook are also considered development platforms.  
- A virtual machine (VM) such as the Java virtual machine or .NET CLR. 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. 
- AmigaOS, AmigaOS 4
- Chrome OS
- FreeBSD, NetBSD, OpenBSD
- IBM i
- Microsoft Windows
- Classic Mac OS - discontinued in 2011
- Tru64 UNIX
- Bada - discontinued in 2013
- BlackBerry OS - discontinued in 2013
- Fire OS
- Firefox OS - discontinued in 2016
- Embedded Linux
- Palm OS - discontinued in 2011
- Symbian - discontinued in 2012
- Windows Mobile - discontinued in 2010
- Windows Phone - discontinued in 2017
- Binary Runtime Environment for Wireless (BREW)
- Cocoa Touch
- Common Language Infrastructure (CLI)
- Java platform
- Microsoft XNA
- Mozilla Prism, XUL and XULRunner
- Web platform
- Oracle Database
- SAP NetWeaver
- Universal Windows Platform
Ordered roughly, from more common types to less common types:
Commodity computing platforms
ARM architecture based devices
- Android smartphones
- iPhone smartphones and iPad tablet devices running iOS or iPadOS, from Apple
- Macintosh computers using Apple silicon.
- Raspberry Pi or Gumstix full function miniature computers with Linux
- ARM servers with Unix-like systems such as Linux or BSD variants
- Newton devices running the Newton OS, from Apple
- ChromeBooks from various manufacturers
- Wintel, that is, Intel x86 or compatible personal computer hardware with Windows operating system
- Macintosh, custom Apple Inc. hardware and Classic Mac OS and macOS operating systems, originally 68k-based, then PowerPC-based, then x86-based, now migrated to Apple silicon with ARM architecture CPUs
- x86 with Unix-like systems such as Linux or BSD variants
- CP/M computers based on the S-100 bus, maybe the earliest microcomputer platform
- ARM architecture based devices
- Video game consoles, any variety ( PlayStation, Xbox, Nintendo)
Itanium processor based machines
- Unix variants or Unix-like systems
- PowerPC or Power ISA computers running IBM i
- DEC Alpha and Itanium computers running OpenVMS
- Midrange computers with their custom operating systems
- Mainframe computers with their custom operating systems, such as IBM z/OS
- Supercomputer architectures
- "What I Talk About When I Talk About Platforms". martinfowler.com. Retrieved 2018-03-18.
- " platform". Free On-line Dictionary of Computing
- Andrew Binstock (July 2, 2012). "Google's Redefinition of the Browser As Platform". Dr. Dobbs.
- Chip Wilson; Alan Josephson. "Microsoft Office as a Platform for Software + Services". Microsoft Developer Network.
- "What Is PAAS?". Interoute.
- "Twitter Development Platform - Twitter Developers".
- "Facebook Development Platform Launches..." Facebook. August 15, 2006.
- "Platform independence in Java's Byte Code". Stack Overflow.
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