That's not what I meant by "building from source" and you know it.

Huh? I was just pointing out that the distance between building a binary from a mess of source files and building a web app from - er - a mess of source files is not that huge.

And the trend is for it to get less huge.

E.g. Bootstrap already uses the words "custom build" for a rebuild, and js-world has gulp and grunt for "building".

There's already been serious talk about either throwing out the DOM or abstracting it with something closer to a native code model.

Honestly, I'll be surprised if this doesn't happen within the next few years.

And that has nothing to do with users using the software. My point was that you can make even C code "cross platform", with a lot of effort, if you make the user build the program from source. But that is just about the worst possible experience for the user. Building cross platform applications as browser SPAs is easier on both the developer and the user.

> Given the snarly mess of frameworks/tools/languages/abstractions used in web dev, it's not obvious you'd get worse performance or inferior code using JIT LLVM and some newly minted update of Visual Basic or Swift with component/object/view caching.

What is obvious, however, is that more users have a Web browser on whatever device they want to use to use your software than have a virtual machine environment for any language besides JavaScript.