mongrel VS Tokamak

The other major thing you'll run into is performance. WEBrick's HTTP parsing code may look hairy but it is fast. Mongrel was the first Ruby HTTP server to implement it's HTTP parser in C using Ragel, which Thin, Unicorn, and Puma all copied; although there's a bug in the original Mongrel HTTP parser where it does not combine the values duplicate HTTP headers (yes, HTTP Header names can actually be repeated).

https://github.com/TokamakUI/Tokamak

I’m also working (slowly) on native Flutter channels:

https://github.com/PADL/FlutterSwift

But this is really targeted at embedded use cases.

There is Tokamak but I don't know how usable it is just yet.

TokamakUI runs via SwiftUI on WASM for web. Apple just hired the creator of the framework.

You can even make web apps by creating web components in swift with Tokamak.

I am playing around with Tokamak just for a bit of fun and learning, and it's been pretty solid so far! Though I want to branch out and play with some dynamic data from a random API, instead of just using mocked/pre-populated data.

There is SwiftWasm that compiles swift into WebAssembly so you can run it in the browser, but swift can't directly manipulate the DOM so you'd still need JavaScript or something like TokamakUI so you can design the front-end portion of your app.