| bytes | Package bytes implements functions for the manipulation of byte slices. |
| 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/godoc/static | Package static exports a map of static file content that supports the godoc user interface. |
| golang.org/x/tools/playground/socket | Package socket implements an WebSocket-based playground backend. |
| golang.org/x/tools/present | The present file format |
| 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/ioutil | Package ioutil implements some I/O utility functions. |
| log | Package log implements a simple logging package. |
| net | Package net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets. |
| net/http | Package http provides HTTP client and server implementations. |
| net/url | Package url parses URLs and implements query escaping. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| path/filepath | Package filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| sort | Package sort provides primitives for sorting slices and user-defined collections. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| time | Package time provides functionality for measuring and displaying time. |