| archive/zip | Package zip provides support for reading and writing ZIP archives. |
| 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/get | |
| cmd/go/internal/lockedfile | Package lockedfile creates and manipulates files whose contents should only change atomically. |
| 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/par | |
| cmd/go/internal/renameio | |
| cmd/go/internal/robustio | |
| cmd/go/internal/str | Package str provides string manipulation utilities. |
| cmd/go/internal/web | Package web defines minimal helper routines for accessing HTTP/HTTPS resources without requiring external dependencies on the net package. |
| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| 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/mod/modfile | Package modfile implements a parser and formatter for go.mod files. |
| golang.org/x/mod/module | Package module defines the module.Version type along with support code. |
| golang.org/x/mod/semver | Package semver implements comparison of semantic version strings. |
| golang.org/x/mod/sumdb | Package sumdb implements the HTTP protocols for serving or accessing a module checksum database. |
| golang.org/x/mod/sumdb/dirhash | Package dirhash defines hashes over directory trees. |
| golang.org/x/mod/sumdb/note | Package note defines the notes signed by the Go module database server. |
| golang.org/x/mod/zip | Package zip provides functions for creating and extracting module zip files. |
| internal/lazyregexp | Package lazyregexp is a thin wrapper over regexp, allowing the use of global regexp variables without forcing them to be compiled at init. |
| io | Package io provides basic interfaces to I/O primitives. |
| io/ioutil | Package ioutil implements some I/O utility functions. |
| net/url | Package url parses URLs and implements query escaping. |
| 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. |
| 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. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| time | Package time provides functionality for measuring and displaying time. |