Package hex implements hexadecimal encoding and decoding.

Package json implements encoding and decoding of JSON as defined in RFC 7159.

Package pem implements the PEM data encoding, which originated in Privacy Enhanced Mail.

Package xml implements a simple XML 1.0 parser that understands XML name spaces.

Package errors implements functions to manipulate errors.

Package expvar provides a standardized interface to public variables, such as operation counters in servers.

Package flag implements command-line flag parsing.

Package fmt implements formatted I/O with functions analogous to C's printf and scanf.

Package ast declares the types used to represent syntax trees for Go packages.

Package build gathers information about Go packages.