Judging from your items in the list, it looks like you started with Mozilla's mortar library , which I work on, and completely rebuilt it. I really like how you've structured it and all the stuff you've included -- it's a much more powerful starting point than what we currently have with mortar.
We've been hard at work trying to figure out what we should do with mortar. Naturally several other starting points have emerged, because that's how the web works. We're excited about this. We, Mozilla, still want to give developers something they can use to easily get started, but we'll most likely refer to all the other ones too so the developer can choose between lots of libraries (ember, angular, requirejs, etc).
Thanks for this, I'll keep it in mind as we write documentation on MDN for writing Firefox OS apps!
Paragraph 1: Ok, so we have some serious competition.
2: We are not going to beat them, we are changing the game.
3: There is massive developer potential.
4: Html sucks, or does it?
5: Frameworks and compile-to-js save the day!
6: Not just HTML5, standardized HTML5!
7: Fixing the problem of "Several languages, frameworks, APIs" and "vendor lock-ins"
8: Mozilla can be trusted.
The released version will not just be targeted at developers. Right now there is a Firefox OS developer phone  that you can get, but when it officially comes out it will be a fully-featured phone targeted at low prices.
See, this is why we have so many problems on the web. People targeting one specific browser and completely ignoring the rest despite it working perfectly fine in all of them if they just stopped to include some other prefixes.
DON'T make apps for chrome. Hell, don't make apps for FirefoxOS either. Make apps for the web. Make them work everywhere, and stop trying to make "one render engine to rule them all" happen, because it's bad for the whole ecosystem.
As a dev on Firefox OS I had been trying to disuade us from promoting / people from using the 'Building Blocks' ui library, it makes sense for the OS itself to use it but for 3rd parties "I hope this becomes a bygone of separate apps per platform"
I lost that, but I think it will come around as the platform matures, I will always just be building web apps
>See, this is why we have so many problems on the web
Your problem is that browsers are a very restrictive sandbox (so you can't extend stuff yourself, you have to wait for the browser vendors to implement it) and the standards process is glacially slow. People seem to want to use the web as a platform for general purpose software. The current standards are not good enough. So inevitably people look to browser specific features because they want to make stuff that actually works now rather than waiting possibly years for features to be standardised and implemented in every browser. It seems very unrealistic to expect people to cripple their software just to stay 'standards compliant'. History seems to indicate that people will use the available tools to solve their problems. A few purists will shout from the sidelines while everybody else gets on with doing real work.
To put it another way: targeting one browser gives you a competitive advantage because that is where cutting edge and interesting features are, and that isn't going to change any time soon unless there is a big change to the standards process. Hence "Made for Chrome", "Best viewed on Chrome" and soon "Made for FirefoxOS".