In computing, cross-platform, or multi-platform, is an attribute conferred to computer software or computing methods and concepts that are implemented and inter-operate on multiple computer platforms. Cross-platform software may be divided into two types; one requires individual building or compilation for each platform that it supports, and the other one can be directly run on any platform without special preparation, e.g., software written in an interpreted language or pre-compiled portable bytecode for which the interpreters or run-time packages are common or standard components of all platforms.
For example, a cross-platform application may run on Microsoft Windows on the x86 architecture, Linux on the x86 architecture and Mac OS X on either the PowerPC or x86 based Apple Macintosh systems. A cross-platform application may run on as many as all existing platforms, or on as few as two platforms.
Read more about Cross-platform: Platforms, Cross-platform Software, Platform-independent Software, Cross-platform Programming, Challenges To Cross-platform Development