| bytes | Package bytes implements functions for the manipulation of byte slices. |
| encoding/binary | Package binary implements simple translation between numbers and byte sequences and encoding and decoding of varints. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| image | Package image implements a basic 2-D image library. |
| image/color | Package color implements a basic color library. |
| io | Package io provides basic interfaces to I/O primitives. |
| io/ioutil | Package ioutil implements some I/O utility functions. |
| sort | Package sort provides primitives for sorting slices and user-defined collections. |