| bytes | Package bytes implements functions for the manipulation of byte slices. |
| 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. |
| math/big | Package big implements arbitrary-precision arithmetic (big numbers). |
| net | Package net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| reflect | Package reflect implements run-time reflection, allowing a program to manipulate objects with arbitrary types. |
| syscall | Package syscall contains an interface to the low-level operating system primitives. |