| encoding/binary | Package binary implements simple translation between numbers and byte sequences and encoding and decoding of varints. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| golang.org/x/net/bpf | Package bpf implements marshaling and unmarshaling of programs for the Berkeley Packet Filter virtual machine, and provides a Go implementation of the virtual machine. |
| golang.org/x/net/internal/iana | Package iana provides protocol number resources managed by the Internet Assigned Numbers Authority (IANA). |
| golang.org/x/net/internal/socket | Package socket provides a portable interface for socket system calls. |
| golang.org/x/sys/unix | Package unix contains an interface to the low-level operating system primitives. |
| net | Package net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| syscall | Package syscall contains an interface to the low-level operating system primitives. |
| time | Package time provides functionality for measuring and displaying time. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |