So this question is kind of a big one I guess. The goal of the project I'm working is to create an entirely new OS. Obviously writing one from scratch in this day in age is kind of a waste of time, so I thought I'd base it off Ubuntu.
I'm pretty much planning on editing everything via the source code, (no customization programs, this OS needs to have an ISO file at the end that you can burn to a CD, without any of my personal files, but with all of the features and programs that I plan to write. No strings attached.) How would I go about doing this? I know many programming languages, so I think it's just a matter of getting the source code and editing it. I've done some preliminary research on this, but I can't quite figure out how to get it done. Secondly, I'd like to build new packages to have on the default OS (end product). These aren't just nifty programs, but actual OS features (like the unity bar, that's a prime example of a program I might make). How would I go about this?