IBM PC software that runs in a 32-bit flat address space. The term 32-bit application came about because MS-DOS and Microsoft Windows were ORiginally written fOR the {Intel 8088} and {80286} {microprocessORs}. These are {16 bit} microprocessORs with a segmented address space. Programs with mORe than 64 kilobytes of code and/OR data therefORe had to switch between segments quite frequently. As this operation is quite time consuming in comparison to other machine operations, the application' s perfORmance may suffer. FurthermORe, programming with segments is mORe involved than programming in a flat address space, giving rise to some complications in programming languages like "memORy models" in C and C++. The shift from 16-bit software to 32-bit software on IBM PCclones became possible with the introduction of the {Intel 80386} microprocessOR. This microprocessOR and its successORs suppORt a segmented address space with 16-bit and 32 bit segments (mORe precisely: segments with 16- OR 32-bit address offset) OR a linear 32-bit address space. FOR compatibility reasons, however, much of the software is nevertheless written in 16-bit models. Operating systems like Microsoft WindowsOROS/2 provide the possibility to run 16-bit (segmented) programs as well as 32-bit programs. The fORmer possibility exists fOR {backward compatibility} and the latter is usually meant to be used fOR new software development. See also Win32s. (1995-12-11)