$ go tool dist list
android/386                                  linux/s390x
android/amd64                                nacl/386
android/arm                                  nacl/amd64p32
android/arm64                                nacl/arm
darwin/386                                   netbsd/386
darwin/amd64                                 netbsd/amd64
darwin/arm                                   netbsd/arm
darwin/arm64                                 openbsd/386
dragonfly/amd64                              openbsd/amd64
freebsd/386                                  openbsd/arm
freebsd/amd64                                plan9/386
freebsd/arm                                  plan9/amd64
linux/386                                    plan9/arm
linux/amd64                                  solaris/amd64
linux/arm                                    windows/386
linux/arm64                                  windows/amd64
linux/js  <- Over here!
linux/mips64
linux/mips64le
linux/ppc64
Go gopher by Renee French.