Not sure to find a proper introduction to this topic but it’ll be one shot … Newly came to ubuntu-mate moving from canonical’s after 2 years using it I loved ubuntu from the very moment I experienced it but never had a chance to get to the core of it although I’m a computer science student and have a good background of programming I feel like lost when it comes to get to the technical part of linux ( ubuntu to be more specific ) I tried to get any help by posting similar topics to askubuntu ( when I was a canonical’s product user ) but users there are less friendly and always they point either if its off-topic or to learn coding which I already know .
so if any one can guide me to a good source where I can learn the core of linux how to build it ? how to modify it ? I will be grateful 
Here’s a place to start: https://github.com/vhf/free-programming-books/blob/master/free-programming-books.md#linux
I also recommend “The Linux Programming Interface”, an excellent book.
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Hi @Amr.Magdy,
see also (not sure if it is what you want/need?):