OS returns a StatSource that includes various operating system process data such as the number of file descriptors.

Proc returns a StatSource that includes various operating system process data from /proc if available.

Process returns a StatSource including generic process data, such as the process uptime, and a crc of the executing binary if possible.

Register attaches all of this package's environment data to the given registry.

Runtime returns a StatSource that includes information gathered from the Go runtime, including the number of goroutines currently running, and other live memory data.

Rusage returns a StatSource that provides as many statistics as possible gathered from the Rusage syscall.