* child_process.exec(command[, options], callback)
* child_process.execFile(file[, args][, options][, callback])
child_process.execFile() is similar to child_process.exec() except it does not execute a subshell
but rather the specified file directly.
This makes it slightly leaner than child_process.exec.
* child_process.fork(modulePath[, args][, options])
This is a special case of the spawn() functionality for spawning Node processes.
In addition to having all the methods in a normal ChildProcess instance,
the returned object has a communication channel built-in.
These child Nodes are still whole new instances of V8.
Assume at least 30ms startup and 10mb memory for each new Node.
That is, cannot create many thousands of them.