Update documentation to point out the option to use TeaVM instead of GWT

[mipastgt]

Please update the documentation to point out the option to use TeaVM instead of GWT. GWT has always been the killer argument for not using this project.

[salmonb]

The documentation has been updated to mention that TeaVM can be used as an alternative to GWT, and how.

Regarding GWT, it’s worth clarifying that it's still maintained and actively used. In practice, GWT consistently produces significantly more compact JavaScript output than TeaVM, as shown in the comparison table now included in the documentation.

It’s also worth noting that a new GWT release is currently in progress, which further reflects ongoing maintenance and activity around the project.

Both backends remain supported, and users can choose the one that best fits their constraints.

If you try the TeaVM setup, feedback on the documentation or your experience is welcome.

[mipastgt]

For fairness one should probably mention that you can do with Kotlin compose multiplatform (CMP) exactly what you can do with WebFX instead of writing "Some alternative technologies or JVM languages allow you to do the same but only for the application logic, because they don’t offer a cross-platform UI toolkit.". CMP does offer a UI toolkit.

[salmonb]

Good point — when I first wrote this section, Kotlin Multiplatform existed but Compose Multiplatform did not yet provide a shared UI toolkit. You’re right that CMP now offers shared UI code.

However, CMP has not reached the same level of UI abstraction as WebFX. WebFX provides a single Java UI API compiled across all platforms, whereas CMP still relies on platform-specific UI backends, even when sharing a common programming model (Skia-based on Desktop, native UIKit/SwiftUI bridges on iOS, DOM/Canvas/Wasm on the Web). This architectural difference is a key point.

I’ve clarified the wording in the documentation to better reflect the current situation. It now says:

Some alternative technologies or JVM languages also support cross-platform development, but rely on platform-specific UI implementations rather than compiling from a single UI API.

[mipastgt]

Sorry, but that statement is plain wrong. CMP does offer a single UI API across all (major) platforms. What you have cited are options. E.g. on iOS you have the option to either use native UI or the unified compose UI. The same for the two web platforms. I have written applications myself which have the same unified compose UI, using the same source code, for macOS, Windows, Linux, Android, iOS, WASM adn JS.

https://kotlinlang.org/compose-multiplatform/

[salmonb]

Ok, thanks for spotting this, I wasn’t fully up-to-date regarding CMP’s capabilities.

So I’ve just removed the statement from the docs to keep it accurate.