Standard Apple Numerics Environment

Standard Apple Numerics Environment (SANE) was Apple Computer's software implementation of. It was first available for the 6502-based Apple II and Apple III models and came standard with the 65816-based Apple II GS and 68k-based Lisa and Macintosh models. Later Macintosh models had hardware support through discrete 68881/68882 math coprocessors or floating-point units (FPUs) built directly into high-end 68040 processors. However, SANE was still made available for compatibility with existing software, especially when run on entry-level systems that did not have hardware FPUs, such as the lower-end 68LC040 processors.

SANE was eventually phased out as Apple switched from 680x0 to PowerPC processors which had built-in floating point units. However, when running older 68k software on a PowerPC system, only a 68LC040 processor without an FPU was emulated, causing software that neglected to perform a hardware check to fail. In such cases, a floating-point emulator like SoftwareFPU would be required.