| bufio | Package bufio implements buffered I/O. |
| bytes | Package bytes implements functions for the manipulation of byte slices. |
| compress/gzip | Package gzip implements reading and writing of gzip format compressed files, as specified in RFC 1952. |
| io | Package io provides basic interfaces to I/O primitives. |
| os/exec | Package exec runs external commands. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |