Look at Intel, for crying out loud. Has there been anything really interesting / exciting coming out from Intel for the past decades??
The Core micro-architecture was within the last decade and that was very interesting and exciting. Sandy Bridge was also a pretty good milestone.
What's the power density? (Amount of energy delivered over time)
That's not power density. That's just power. Power density is how much power (energy delivered over time) it can deliver per unit volume of battery. That's really only of concern for high power applications such as an electric race car. For most usages, energy density is far more valuable.
I'm not sure why you view changing a battery once or twice a year as such a big deal.
It's because it generally means replacing your whole phone these days.
The difference between project hosting and a "service to host and edit source code repositories" is a few wiki pages for a description and documentation.
You're forgetting about an issue tracker.
With your bare hands?!?
