| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| log | Package log implements a simple logging package. |
| math | Package math provides basic constants and mathematical functions. |
| net/http | Package http provides HTTP client and server implementations. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| sort | Package sort provides primitives for sorting slices and user-defined collections. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| sync/atomic | Package atomic provides low-level atomic memory primitives useful for implementing synchronization algorithms. |
| unicode/utf8 | Package utf8 implements functions and constants to support text encoded in UTF-8. |