Hi Greg, Tayseer.... > It's evolutionary design, not formal design. And it works. Really > well. I'm sure you can agree. Maybe this is what people call "Extreme Programming"? ;) BTW, something like graphviz, lxr, doxygen, ctags/cscope are really helpful to understand Linux kernel internal. Codes speak for themselves, yes I moderately agree, but without proper formal documentation and/or UML/DFD/whatever....newcomer will find it hard to understand how Linux kernel. OTOH, I also realize that OS development is a complex stuff. It can be compared to the complexity of game development (in user space) IMHO. Last, books ( i mean good books) are always needed. Greg, I owe you one for writing LDD3 together with Mr Corbet and Mr Rubini. Any plan for LDD4? ;) regards Mulyadi -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/