Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines.

Package cgo contains runtime support for code generated by the cgo tool.

Package coverage.

Package debug contains facilities for programs to debug themselves while they are running.

Package metrics provides a stable interface to access implementation-defined metrics exported by the Go runtime.

Package pprof writes runtime profiling data in the format expected by the pprof visualization tool.

Package race implements data race detection logic.

Package trace contains facilities for programs to generate traces for the Go execution tracer.

Package slices defines various functions useful with slices of any type.

Package sort provides primitives for sorting slices and user-defined collections.