My jaw dropped on the byte code slides. Even though probably foolish to expect that the Javascript creator would offer non-Javascript solutions, I would guess that it would be significantly better to compile Javascript/CSS to a more efficient, stable, portable target byte code or source language (Go? Scheme? Postscript?) than to compile languages to Javascript. For example, when I played with it the Hello World ClojureScript example compiled to a Javascript file of over 100kbytes. It seems like Go and JIT'ed languages have demonstrated that extremely fast compilation of extremely efficient high level native code is possible.
Long-term it seems like it would be significantly better to encode these web language extensions (new CSS/Javascript syntax) as libraries instead of as API/run-time extensions so that each new version of web languages doesn't require all the run-times (Firefox, Chrome, Safari, IE) to adopt it and old run-times to phase out. The current standards/run-time process doesn't seem to be extremely well-thought out. Has anyone on these standards communities ever had to actually build or maintain a web application?
Long-term it seems like it would be significantly better to encode these web language extensions (new CSS/Javascript syntax) as libraries instead of as API/run-time extensions so that each new version of web languages doesn't require all the run-times (Firefox, Chrome, Safari, IE) to adopt it and old run-times to phase out. The current standards/run-time process doesn't seem to be extremely well-thought out. Has anyone on these standards communities ever had to actually build or maintain a web application?