| 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. |
| crypto | Package crypto collects common cryptographic constants. |
| crypto/rand | Package rand implements a cryptographically secure random number generator. |
| crypto/rsa | Package rsa implements RSA encryption as specified in PKCS #1 and RFC 8017. |
| crypto/sha1 | Package sha1 implements the SHA-1 hash algorithm as defined in RFC 3174. |
| crypto/x509 | Package x509 implements a subset of the X.509 standard. |
| crypto/x509/pkix | Package pkix contains shared, low level structures used for ASN.1 parsing and serialization of X.509 certificates, CRL and OCSP. |
| encoding/asn1 | Package asn1 implements parsing of DER-encoded ASN.1 data structures, as defined in ITU-T Rec X.690. |
| encoding/base64 | Package base64 implements base64 encoding as specified by RFC 4648. |
| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| encoding/pem | Package pem implements the PEM data encoding, which originated in Privacy Enhanced Mail. |
| encoding/xml | Package xml implements a simple XML 1.0 parser that understands XML name spaces. |
| errors | Package errors implements functions to manipulate errors. |
| flag | Package flag implements command-line flag parsing. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| golang.org/x/mobile/internal/binres | Package binres implements encoding and decoding of android binary resources. |
| golang.org/x/mobile/internal/sdkpath | Package sdkpath provides functions for locating the Android SDK. |
| golang.org/x/mod/modfile | Package modfile implements a parser and formatter for go.mod files. |
| golang.org/x/sync/errgroup | Package errgroup provides synchronization, error propagation, and Context cancelation for groups of goroutines working on subtasks of a common task. |
| golang.org/x/tools/go/packages | Package packages loads Go packages for inspection and analysis. |
| hash | Package hash provides interfaces for hash functions. |
| html/template | Package template (html/template) implements data-driven templates for generating HTML output safe against code injection. |
| io | Package io provides basic interfaces to I/O primitives. |
| io/fs | Package fs defines basic interfaces to a file system. |
| io/ioutil | Package ioutil implements some I/O utility functions. |
| log | Package log implements a simple logging package. |
| math/big | Package big implements arbitrary-precision arithmetic (big numbers). |
| os | Package os provides a platform-independent interface to operating system functionality. |
| os/exec | Package exec runs external commands. |
| 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. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| 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. |
| text/template | Package template implements data-driven templates for generating textual output. |
| time | Package time provides functionality for measuring and displaying time. |
| unicode | Package unicode provides data and functions to test some properties of Unicode code points. |
| unicode/utf8 | Package utf8 implements functions and constants to support text encoded in UTF-8. |