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+The following three lists are compiled from:
+[Nim/compiler/plataform.nim](https://github.com/nim-lang/Nim/blob/devel/compiler/platform.nim) and
+[Nim/compiler/extccomp.nim](https://github.com/nim-lang/Nim/blob/1ad729ee3b4738cffcbf0009e8849cb57b729e91/compiler/extccomp.nim)
+
+One can use some name from them like:
+```nim
+when defined(Windows):
+  doSomething()
+```
+
+### Operating Systems:
+* ``DOS``
+* ``Windows``
+* ``OS2``
+* ``Linux``
+* ``MorphOS``
+* ``SkyOS``
+* ``Solaris``
+* ``Irix``
+* ``NetBSD``
+* ``FreeBSD``
+* ``OpenBSD``
+* ``AIX``
+* ``PalmOS``
+* ``QNX``
+* ``Amiga``
+* ``Atari``
+* ``Netware``
+* ``MacOS``
+* ``MacOSX``
+* ``Haiku``
+* ``VxWorks``
+* ``JS``
+* ``NimrodVM``
+* ``Standalone``
+
+### CPU Architectures:
+* ``i386``
+* ``m68k``
+* ``alpha``
+* ``powerpc``
+* ``powerpc64``
+* ``sparc``
+* ``vm``
+* ``ia64``
+* ``amd64``
+* ``mips``
+* ``arm``
+* ``js``
+* ``nimrodvm``
+* ``avr``
+
+
+### Compilers:
+
+
+* ``vcc``           Microsoft's Visual C++
+* ``gcc``           Gnu C
+* ``llvm_gcc``      LLVM-GCC compiler
+* ``icc``           Intel C++ compiler
+* ``clang``         Clang compiler
+* ``bcc``           Borland C Compiler
+* ``dmc``           Digital Mars C Compiler
+* ``wcc``           Watcom C Compiler
+* ``tcc``           Tiny C Compiler
+* ``pcc``           Pelles C Compiler
+* ``ucc``           Generic UNIX C compiler
+
+
+# compileOption
+
+Also remember about how to access the [compiler options](http://nim-lang.org/docs/nimc.html):
+```nim
+  when compileOption("boundChecks"):  # d:release should disable this.
+    if i > q.high:  # x < q.low is taken care by the Natural parameter
+      raise newException(IndexError, "Bla has less than " & $(i+1) & " elements.")
+  discard
+```
+
+TODO: List them here and how to correctly access the more complex ones.
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