| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| golang.org/x/sys/windows | Package windows contains an interface to the low-level operating system primitives. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| time | Package time provides functionality for measuring and displaying time. |
| unicode/utf16 | Package utf16 implements encoding and decoding of UTF-16 sequences. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |