| archive/zip | Package zip provides support for reading and writing ZIP archives. | 
    | 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. | 
    | encoding | Package encoding defines interfaces shared by other packages that convert data to and from byte-level and textual representations. | 
    | encoding/binary | Package binary implements simple translation between numbers and byte sequences and encoding and decoding of varints. | 
    | encoding/xml | Package xml implements a simple XML 1.0 parser that understands XML name spaces. | 
    | errors | Package errors implements functions to manipulate errors. | 
    | fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. | 
    | io | Package io provides basic interfaces to I/O primitives. | 
    | os | Package os provides a platform-independent interface to operating system functionality. | 
    | path | Package path implements utility routines for manipulating slash-separated paths. | 
    | 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. | 
    | strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. | 
    | unicode | Package unicode provides data and functions to test some properties of Unicode code points. | 
    | unicode/utf16 | Package utf16 implements encoding and decoding of UTF-16 sequences. |