Whither Web programming?

The web browser provides a platform with unmatched reach, but it still suffers from annoying limitations. Building major web applications has been extraordinarily challenging. For the web to thrive, it needs to be competitive with native platforms across the board, especially on mobile devices.   The web must make it easy to develop applications that run on- and off-line, and that provide a first class user experience in terms of performance, features and UI while requiring essentially zero maintenance from the user. Key to this is developer productivity.   Happily, things are getting better. Programmers can expect better performance, better APIs and a great diversity of viable programming languages and tools: IDEs that support live programming in the browser; interesting languages that are not just minor variations on Javascript but actually make programmers significantly more productive; civilized UI frameworks and so on.   We'll show several such systems, some viable today, some more radical, and discuss what is holding them back.   Things are just starting to get interesting!