make internals and parallelization

[Michael Muratet]

Greetings

I have been searching the list archives looking for information on how  
make implements parallelization with make -j. From a most global view,  
it appears that there is a data structure of dependancies and multiple  
branches from the root are candidates for parallel processing. I  
haven't seen any mention of a developer's manual, is there one? Can  
anyone point me to some documentation or explain the process?

Thanks

Mike