Facebook's answer to cross platform app development:

A Deep Dive on React Native

I dragged through the whole presentation, still some good ideas caught my attention.

1. Make use of platform tool kit instead of emulating them with HTML5.
2. Use a custom layout engine to build the view tree.
3. Incremental tree rebuild.

Happy to see the industry looking for more pleasant ways of building apps. I have also been thinking on the problem for quite a while.

My wish list for an ultimate solution (at least for the next 30 years):

1. App can be inspected and changed on the fly, no need to relaunch for non-primitive modifications. Think of how sculptors work, or even better, gardeners.
2. Built-in revision control. git still feels too heavy.
3. One source and can be adapted to different platforms. Think of how we use CSS prefixes for different platforms. Not pretty, but useful.
4. Auto recalculation, connection between state and display elements should be seemless. Think of Excel.
5. Text editors are no longer our primary tools.
6. Stay close to metal.

One more thing, javascript won't be fundamental in my solution, because it's just not simple enough.