C# (with .NET Core 3.0 officially launching on the 23rd of September, Blazor (WASM) support is included.) I have been playing around with Blazor a bit with the preview releases and I have to say it's pretty slick.
Does JavascriptCore support running wasm (on ios and android) ?
Also, as i mentioned in another answer, i'm not only concerned about being able to run the code on another platform, but also having it run on an "friendly" environment (with some kind of cross-platform I/O api).
You can avoid that issue with the Server Side Blazor concept for business side portions of your application.
Depending on the application you can get extremely far with just using HTTP requests to an API for anything business logic related. A lot of apps over complicate themselves by trying to force a JS framework on the front end with no benefit to the user. I seem to prefer using non-SPAs these days over SPAs because very few places do them well. Google being a terrible SPA developer.
- Edit - I forgot to mention Elixir's Phoenix has LiveView which is similar to Server Side Blazor.
As I understood Blazor as compiled business logic rather than a bundled runtime is due in a future release of .Net Core. Not sure if it's ready for 3.0 later this month but that will be the game-changer Blazor promises to be. Yes, Phoenix Live View is similar but unfortunately Elixir hasn't really captured sufficient mindshare for it to have an impact.
I have a data web-app heavy app where users will routinely view over 300MB of data in charts and photos.
In this context, .net runtime is insignificant. In fact, you could could argue such data intensive applications should be native and use local storage.
Lastly, the browser with cache .Net runtime, and won't download it very often.
Also, as i mentioned in another answer, i'm not only concerned about being able to run the code on another platform, but also having it run on an "friendly" environment (with some kind of cross-platform I/O api).