[erlang-questions] how are erlang process lightweight?

[Ben Dougall]

So to sum up, from an implementation of Erlang processes point of view, 
Erlang processes are _very_ similar to threads apart from:

	- each process/thread has it's own memory space which is never shared 
with others, and they communicate via message passing.
	- the mechanics of the process/thread is not handled by the OS outside 
user space, but by the Erlang runtime system in user space -- inside 
the programme's process(that use of "process" being the normal unix 
one).

And the savings of doing all the switching etc. in user space is a main 
reason Erlang processes can be so lightweight. That, and also the loss 
of the need for locks etc.

Thanks, Ben.