| C | |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| 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. |
| syscall | Package syscall contains an interface to the low-level operating system primitives. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |