alpha
amd64
amd64-fbsd
arm
arm64
hppa
ia64
m68k
mips
ppc
ppc64
s390
sh
sparc
x86
x86-fbsd

# Prefix keywords
ppc-aix
amd64-linux
arm-linux
arm64-linux
ppc64-linux
x86-linux
ppc-macos
x86-macos
x64-macos
m68k-mint
sparc-solaris
sparc64-solaris
x64-solaris
x86-solaris
x86-winnt
x64-cygwin
x86-cygwin