Java Web Start (JNLP) worked great. It just worked. His customers loved him.
I've always wondered why something like desktop JNLP didn't happen.
JNLP did a good job of solving the app distribution/update problem, but required that you already had the JRE installed. Not too much different from assuming a browser is installed, but I found it much less likely that a user would take the initiative to install a JRE than a browser. They just don't understand what they are doing or why in the case of the language runtime.
That said, it did work very well, in my experience.
A jnlp app is a file format that defines how to launch a java executable over the internet. It defines the location where the executable is, and what version of java is required. Opening the jnlp to download and launching the app requires an installed JRE, or there is nothing to interpret the jnlp and go get the application.
There is, iirc, a utility that will wrap a jnlp file and go get a jre. I forget what it's called, but it makes jnlp apps more like an auto-updating standard app.
The benefit of the jnlp approach is if you can guarantee your users have java installed, then they don't need to install your app. Just click a link, then a java app self-downloads, installs and sets up a shortcut on the desktop. And it updates whenever they open it and a new version is detected.
Wasn’t that Marimba/Castanet?
A.) ...they never figured out a good/unobtrusive update process for the JVM itself.
B.)...Sun faltered when they picked up steam. (Remember when IBM threw 1 billion USD at writing Eclipse in Java?)
I hear Java GUI has supposedly gotten better, but all of the Java GUI apps I see look awful. For instance, try telling that to Ghidra and it's butt-ugly text that shows up super thin on my hidpi display. I like Ghidra, but for a graphical RE tool, Cutter is so much prettier with its QT interface. Of course, r2 is great and works from CLI.
No one in his right mind loves the UI of Jetbrains Apps and the Linux experience has always been a shitshow unless you were using Gnome or KDE. Because Swing does not implement the XWindows protocol properly. So yeah, a great team can still make a functional app with terrible GUI technology -- but there is a world of a difference to something that's really polished, fast and enjoyable to use.
VsCode and atom are simpler, but they just don't provide UI, for many setting you have to go to config files, and some functionality is missing outright.
Can you think of an IDE with better UX?
I like being able to configure just about everything in just a single config file, but still getting an additional escape hatch for overriding OS default keybindings I want to use.
Also, the menu bar in IntelliJ was reimplemented from scratch to make it work properly. The Swing menu bar would have been unusable with its broken handling of submenus.
I suppose preferences here are at least partially determined by how you think about software project management. Eclipse makes perfect sense to me, and has since the first day I used it. IntelliJ is obtuse and odd and ... wrong to me.
In my imaginary company that I own where we all run linux laptops that are managed by puppet or something, I think we might make a strong case for building many internal tools in Swing.
The biggest hurdle I see nowadays to using Swing is all about distribution: both of the jvm and the program. Imo that's really where the web won - certainly not because of its dev productivity. So it's definitely a no-go for your actual software product.... but for internal tools where you have a lot more leverage over the environment, I think it looks extremely attractive.
Regarding JavaFX... Honestly, I really like it. I have a personal project that was originally in Swing and I ported it to JavaFX because HiDPI is in a lot better shape there (though I think Swing has since figured it out?). And it's a lot better in many ways. I love-love-love using SceneBuilder for designing the view layer and the Observable pattern, I think, yields a lot of nice QOL/verbosity-reducing things.
That said, I think it did have a slightly higher O() for frustration than Swing's O(1). And I think the community, as a whole, just understands it less (less prior art etc).
So if someone said "build a usable high-quality GUI asap or you die" to me, I'd go to Swing immediately.