| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| math | Package math provides basic constants and mathematical functions. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| sync/atomic | Package atomic provides low-level atomic memory primitives useful for implementing synchronization algorithms. |
| time | Package time provides functionality for measuring and displaying time. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |