| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| log/slog | Package slog provides structured logging, in which log records include a message, a severity level, and various other attributes expressed as key-value pairs. |
| net/http | Package http provides HTTP client and server implementations. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| regexp | Package regexp implements regular expression search. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| time | Package time provides functionality for measuring and displaying time. |
| zgo.at/zhttp | |
| zgo.at/zhttp/internal/isatty | Package isatty implements interface to isatty |
| zgo.at/zstd/zdebug | Package zdebug implements functions useful when debugging programs. |
| zgo.at/zstd/znet | Package znet contains utilities for network communication. |