| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| slices | Package slices defines various functions useful with slices of any type. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| syscall | Package syscall contains an interface to the low-level operating system primitives. |