| 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. |
| 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. |
| sync/atomic | Package atomic provides low-level atomic memory primitives useful for implementing synchronization algorithms. |
| syscall | Package syscall contains an interface to the low-level operating system primitives. |