The great thing about Maemo 5 is that, while it -is- open source and you -can- modify and recompile stuff, you usually don't have to. Thanks to the fully functional Xterm - and full Linux stack - you can usually write simple apps or scripts that will change settings, modify behavior, and implement extra functionality -without- having to mess with C++.

So, while those who are experianced can go in and modify things, the rest of us can usually take those modifications, string them together with shell-scripts and Python, and have something that works... WITHOUT all the low-level knowledge and time spent.