I've just crossed again the doc of the daemon flag (http://docs.python.org/library/multiprocessing.html), and it's still quite confusing to newcomers.

daemon
    The process’s daemon flag, a Boolean value. This must be set before start() is called.
    The initial value is inherited from the creating process. [1]
    When a process exits, it attempts to terminate all of its daemonic child processes.

[1] this sentence is weird: since daemonic processes are not allowed to have children, isn't this flag always False in a new Process instance ?
[2] typo, it meant "all of its NON-daemonic child processes" instead, didn't it ?