| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| golang.org/x/image/font | Package font defines an interface for font faces, for drawing text on an image. |
| golang.org/x/image/math/fixed | Package fixed implements fixed-point integer types. |
| golang.org/x/text/encoding/charmap | Package charmap provides simple character encodings such as IBM Code Page 437 and Windows 1252. |
| image | Package image implements a basic 2-D image library. |
| io | Package io provides basic interfaces to I/O primitives. |
| math | Package math provides basic constants and mathematical functions. |
| 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. |