| bufio | Package bufio implements buffered I/O. |
| encoding/json | Package json implements encoding and decoding of JSON objects as defined in RFC 4627. |
| encoding/xml | Package xml implements a simple XML 1.0 parser that understands XML name spaces. |
| 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. |
| golang.org/x/tools/go/buildutil | Package buildutil provides utilities related to the go/build package in the standard library. |
| golang.org/x/tools/go/loader | Package loader loads a complete Go program from source code, parsing and type-checking the initial packages plus their transitive closure of dependencies. |
| golang.org/x/tools/oracle | Package oracle contains the implementation of the oracle tool whose command-line is provided by golang.org/x/tools/cmd/oracle. |
| io | Package io provides basic interfaces to I/O primitives. |
| log | Package log implements a simple logging package. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| runtime/pprof | Package pprof writes runtime profiling data in the format expected by the pprof visualization tool. |