A simply secure OS ?
I use No Script in a Firefox browser running on a Linux distro.
That is as safe as I can make things and that safety comes with strings, or more pertinently, comes without baubles attached.
By crippling the usability and interactive dimension of the internet I am not getting the full pizazz of what those kindly developers intended, but in trading away all that lovely gooey guff, I get something a lot more secure.
I could spend my next five lifetimes trimming away the unnecessary components that make up my OS in the hope I am minimising the attack vectors and still have a system that wants to engage me in more ways than I require.
It is about time the OS scribblers gave each and everyone of its customers the ability to cut everything down to the core and then some, to then allow the most simplest of actions to be carried out, like, accessing your bank account, in black and white, with no gifs, no animations, no "would you like twitter with that"
By offering up a more simple OS and browser, the opportunity to make it really secure is made much easier.
Basically at start up a menu will give you the ability to run the all singing all dancing OS or the tone deaf, two left feet version that is recommended for security sensitive work, as it is far easier to get ten thousand lines of coding right than it is to get ten million.