Does anyone think it'd be a good idea for browsers to support more than one toolset? Right now it's just HTML+CSS+JS, no matter what languages people build on top of that assembly. Elm seems like a neat idea, but based on Paul's post, I dislike the fact that it compiles down to CSS. It seems a disingenuous way to present the language. I'd much rather a browser was simply told this was an application/elm or something…
I still think there are some good ideas in XML/XLST/SAX/XSD/RELAX NG -- but I think it's clear by now that web developers will not, or cannot, leverage the (rather minor) benefits XML can offer over json/javascript (richer datatypes, mostly -- javascript has gotten so fast that I don't think there's any real benefit to xml+sax over JSON in terms of memory/performance -- so once you throw away all your xml tools as well, there are little benefit remaining).
Generally you can implement pretty much anything else on top of javascript. I do think we could use a better/different rendering model -- having documents/HTML as the base isn't a very good idea. Not sure what the answer would/should be -- seeing how Apple abandoned display postscript, I don't think PDF is the way to go -- perhaps something closer to GL?
I'm a bit of a 90s luddite when it comes to "shiny web apps leveraging javascript for max bling" -- I much prefer gracefully-degrading html+css apps slightly augmented with javascript. But for better or worse, the immediate future clearly belongs to "download code over the internet;run it". Currently we're stuck with js+http+dom as the only real write-once-tweak-for-ever-run-most-places alternative. I think short time success will go to frameorsk like Elm and clojurescript that compile-to-the-browser.
And at the rate of progress we seem to have, I don't think we'll see great platform for delivering apps/objects/runable data in the near future. We appear likely to move the visual basic worms of the 90s to javascript worms of the 10s -- never gaining any decent security or privacy -- because there is no demand for it.
Luckily, well-designed "apps" based on html+css+conserative js can still be great, and have great performance, so I'll try and stick with that, and I'll let everyone else continue to design blogs that can't be read without running "actual" code on the client. For no real benefit (to the user -- to those selling ads/behavioural data the benefits are more tangible, but I'm not a user of that -- I'm just a victim of that).
/rant.