1. OS
  WIN32:  _WIN32_ || _WIN32
  LINUX
  APPLE _APPLE_CC_

2. Compiler
  MSVC
  GNUC
  BORL

  2.1 Complier Version
         _MSC_VER
         _GNUC_ _GNUC_MINOR_ GNUC_PATCHLEVEL_
         _BCPLUSPLUS_

3. Architecture
  64  (__x86_64__) || (_M_X64) || (__powerpc64__) || (__alpha__) || (__ia64__) || (__s390__) || (__s390x__)
  32