| archive/zip | Package zip provides support for reading and writing ZIP archives. |
| bufio | Package bufio implements buffered I/O. It wraps an io.Reader or io.Writer object, creating another object (Reader or Writer) that also implements the interface but provides buffering and some help for textual I/O. |
| bytes | Package bytes implements functions for the manipulation of byte slices. |
| cmd/go/internal/base | Package base defines shared basic pieces of the go command, in particular logging and the Command structure. |
| cmd/go/internal/cfg | Package cfg holds configuration shared by multiple parts of the go command. |
| cmd/go/internal/dirhash | |
| cmd/go/internal/imports | |
| cmd/go/internal/modconv | |
| cmd/go/internal/modfetch | |
| cmd/go/internal/modfetch/codehost | Package codehost defines the interface implemented by a code hosting source, along with support code for use by implementations. |
| cmd/go/internal/modfile | |
| cmd/go/internal/modinfo | |
| cmd/go/internal/module | |
| cmd/go/internal/mvs | Package mvs implements Minimal Version Selection. |
| cmd/go/internal/search | |
| cmd/go/internal/semver | |
| encoding/hex | Package hex implements hexadecimal encoding and decoding. |
| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| flag | Package flag implements command-line flag parsing. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| go/build | Package build gathers information about Go packages. |
| io | Package io provides basic interfaces to I/O primitives. |
| io/ioutil | Package ioutil implements some I/O utility functions. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| path | Package path implements utility routines for manipulating slash-separated paths. |
| path/filepath | Package filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths. |
| regexp | Package regexp implements regular expression search. |
| 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/utf8 | Package utf8 implements functions and constants to support text encoded in UTF-8. |