golang.org/x/sys is a Go library (no binaries of its own) supplying
low-level, platform-specific bindings that don't live in the standard
library: Unix syscalls (unix/), Windows API bindings (windows/), Plan
9 bindings (plan9/), and runtime CPU feature detection (cpu/).

License: BSD-3-Clause (see /usr/doc/go-sys-<version>/LICENSE and
PATENTS).