"component" is a pretty generic term - some of the things in the diagram could be said to be "components", such as FDMs like JSBSim or YASim - others are dependencies, i.e. libraries needed to built FlightGear, but not necessarily relevant to end users - this applies to things like plib, OpenAL, OSG etc - these are basically lower level layers of a "pyramid", with FlightGear being at the very top of it.
So it really all boils down to your goals here, and your target audience - identifying "components" means that you need to determine first some sort of classification scheme. Your "OS Layer" would be at the bottom of the pyramid - and libraries like OSG, OpenAL etc would be somewhere in the middle - with SG/FG being at the top.
You could also say that boost is a part of the "framework" layer - because it's used by SimGear and FlightGear.
Otherwise, there are too many concepts mixed here.
Overall, I suggest to split the whole thing up and turn it into a multi-page slide show, that way you can introduce things one by one.
Inkscape sounds like a good choice to me.
Now, for the fgfs component a diagram has to be created but unfortunately I am not that experienced in FlightGear to start creating it. Therefore, I would need someone's help to describe the relations between the different entities within fgfs (AI, FDM, Autopilot, GUI, etc.). Without this help, it will take me a little more time to read the code and create the fgfs component diagram.
don't worry about that, we can provide more pointers, help and support than you can handle
So the main things would be:
- FligthGear entry point (main) in bootstrap.cxx http://wiki.flightgear.org/FlightGear-P ... f_Interest
- FlightGear initialization (command line processing, options, translations)
- FlightGear main loop
- FlightGear subsystems (AI, AP, FDM, Nasal, GUI etc) see fg_init.cxx
- pseudo subsystems (code not yet using SGSubsystem)
- reset/re-init
- termination/shutdown