Python can do both scripts and desktop apps no problems

To be fair, all three can probably do what you're asking for, in building a desktop application. So the real question comes as which flavor of language do you want to write. The only language of the three I can't speak on is Ruby, as I haven't used it.

Python is a "scripting language", but by that token technically so is Javascript. It's an immensely popular language due to its simple syntax, yet complex features as you get better with it. Python can build large-ish applications: web apps, desktop apps, terminal apps, and yes also of course AI, bulk data processing, etc. For GUI applications, I've personally used pyqt (4? 5? 6?)

Much of the same can be said for Javascript. As you said, there are "negative opinions" about JS, but everyone has their opinions (most factually-based) on the goods and bads of languages (although, yes, JS does get more negative opinions than others). Yet, Javascript is still a widely used language, and you'll probably end up needing learning it anyway if you decide to go into web development.

What I personally suggest is this:

• See the learn x in y minutes pages for Python, Javascript, and Ruby. Make sense of the quick-tour of the languages.
• Make a simple project using each of the three languages. Something that just reads something from STDIN, does some work, prints stuff, as an example. This helps you get to know the basics of the syntax, tooling, and quirks of a language, and helps you narrow down which language you'd like to be working further with.
• Pick one of the languages you're leaning in favor of and go build your application. If you come to a point where you feel like the language you choose is no longer suitable for what you wanted to do, you can always retry with another language, and then you will know at least a fair part of more than one language.

All three are scripting language. Don't touch JavaScript, but consider typescript instead. Your requirements are vague, but python should probably be your first choice. It honestly does not matter which one you choose

There's no answer to this. All can do what you want in varying degrees. With Opal you can compile Ruby to JavaScript for your frontend for example. Or with electron you can use JavaScript as desktop application.

You gotta say much more about the actual requirements to make any meaningful comparison.

I think it would help narrow things down if you described what kind of website you want to build.

Spend a week or two with each if you can, even if you don't stick with any you'll be able to tell what parts you did or didn't prefer or found difficult or easy that might help make a more informed choice. You might prefer the language features or syntax of one, but the tool chain or frameworks of another.

desktop application for Windows, macOS, and Linux

Nothing does cross-platform desktop apps as well as Qt.

Definitely not Electron, which is very wasteful of system resources and has endless desktop integration bugs. Not Flutter. Not WxWidgets. Not Gtk. Not any of the various Java or Rust frameworks. Not Dear ImGui. Nothing. (Well, I haven't tried Lazarus yet, but it requires a language that's not on your list, so is probably not relevant here.)

Some of the newer frameworks might shape up eventually, but it would take years of focused effort. This is an area of computing that is difficult to do well.

I’ve been considering Ruby, Python, Golang and JavaScript

Of those languages, I would choose Python with either PySide or PyQt. If my interface needs were very simple, I might also consider Qt Quick, which lets you build GUIs with JavaScript and a declarative language called QML.

Take a look at Dart+Flutter.

Python would be OK. Ruby is nearly dead nowadays. JS itself is used rarely, better consider using TS (however I don't recommend using them for anything other than web frontend). Go is a great language but it's unpopular in GUI development.

Without saying what you want the app to do you can't pick the language, it's like saying what should I make my house out of? wood, concrete, or ice.
Electron is a well known framework for multiplatform apps. It could be your starting point.

You can count Ruby out immediately. Terrible language.

Also replace JavaScript with Typescript. It's strictly superior.

I don't think Go has any mature GUI libraries.

For desktop GUI your main options are:

• Qt, via C++. Probably the best option but if you don't know C++ that's a huge barrier.
• Qt, via Python. Reasonable but Python is quite a shit language. It's very slow and the tooling/infrastructure is absolutely abysmal. Be prepared to bang your head against the wall trying to e.g. get relative imports to work.
• Dart/Flutter. This is quite nice but not super mature for desktop apps. Also the Dart ecosystem is very small so libraries you want may not be available.
• Electron/Typescript. This is quite a good option. Nobody here will recommend this because nerds have a slightly weird hatred of Electron because the minimum download size is like 80MB. But normally it doesn't really matter. Especially for big apps.

For the web frontend you basically want Typescript. For the backend you can use literally any language.

I would recommend Electron for the GUI and Typescript for the web frontend and Electron GUI. It means you can use the same language everywhere and you won't need to even implement the same program twice.

If you're worried about the download size / RAM usage you can look into Tauri which uses your OS's browser engine. I've never used it though.

For a desktop app I would go with none of those.

If cross platform is the goal, the more important question, and independent of the programming language, is which GUI framework you will use.

Your best bet, at least if you are looking for a stable GUI framework, the best candidate may be C++ and Qt. But that's a hassle in its own right - both C++ and Qt.

TypeScript will have some solutions for you, with web rendering as a desktop app. Golang will have Qt bindings or other more experimental/not thoroughly established+popular GUI frameworks.

My personal favorite ecosystem is .NET. It has an official cross-platform UI project MAUI, but without an official Linux target. Community extensions probably exist. Personally, I dislike the way the UI is declared and bound though (XAML).

My current interest, which I have not explored or validate yet, is using .NET but then host a web or Blazor app in it with Webview2. .NET supports cross-boundary programming, crossing web+managed/native development, and crossing web(HTML+JS)+managed.

Most of the time GUI and the framework technology is a hassle. Your question is too broad and unspecific, so there's not a good answer.

If it's not a "serious" project that you depend on [for your livelihood], pick and start with whatever [looks good or interesting] and go from there. If it is a "serious project" do a bit more GUI framework exploration and assessment, and pick and commit to something. If it's a big commitment or risk, do prototyping with your candidates for verification and assessment - beyond the most simple examples, and for your specific usage.

Most people use JavaScript for this nowadays, but most commentary also hates on it.

I'll be real with you. There's a reason JavaScript keeps being chosen despite the hate. It's so much easier and the dev experience is much more polished for creating desktop apps.

The reason it's hated on is that it is running a browser in the background, which people view as too bloated for a desktop app. Moreover, JS tends not to play well with system-wide themeing like GTK or QT.

But in the end, as a developer, you'll be dealing with a lot of messiness going with anything else. If you're up for a challenge, do try other things. But if you just want something that works and looks nice, do Js

Im biased here, ive been learning python for almost 16 months and only dabbled in Javascript and never did any Ruby, but for a first language, i think python is fantastic. Its "easy" enough to keep you feeling like your skill is actually improving, while still being able to do pretty much anything (where performance is not a high priority). I also just think javascript is ugly to look at.

Maybe you should consider a server & client architecture to use the right tool for the right job on each platform.

Definitely JS if you want to also have a website. Use electron to turn your website into an executable for the desktop. Python+qt is ok for Desktop apps, but does not work for a website.

Languages that compile to wasm would also be an option, (e.g. https://egui.rs with rust), but as far as i am aware none of the languages you've listed are in that set. (Only go would even be a contender between python, ruby, js and go)

I would start with Python it'll help demystify a lot of programming terminology and methods. I have managed to avoid JS for now but I have to learn it and for web you need at least a basic amount plus you could prob stay in the JS ecosystem for pretty much everything you want to do. Ruby is cool it's coming back but like Python it tends to be more common on the back-end, that being said there's some really interesting languages that have spun off it.

I would go Python till you hit a wall it'll prob be the GUI then learn JS

If “build the server and client in the same language” is a hard requirement, I believe your only choice is JavaScript…

The tone of the post makes me think you’re newer to programming, so I’ll leave it at that, as extensions to this question can overwhelm quickly, but yeah, JavaScript is a fine language for what you’re doing

Just a bit more perspective for you:

https://survey.stackoverflow.co/2023/#technology-most-popular-technologies

More than half of professional developers use at least some JavaScript, and almost half of us also use Python.

So both of those are likely to be worth the effort to learn.

That said, as a diehard Python programmer, if I was forced to pick a single language to focus on, it would be JavaScript. JavaScript runs almost everywhere, and it specifically is the only decent option in a few places, such as Web app browser code.

But also, while I'm fluent in a couple dozen languages, my preferred go-to language is still Python.

C#. Or Python if you must. Don't use Javascript.

One of the reasons I think JS gets a lot of hate is the tooling is a bit of a mess. If you go that route I encourage you to generate or find a barebones project to start from. Getting that very first "Hello World" app to run can be a massive pain in the ass.

I also don't think the requirement to a desktop app and website in the same language is being fair. It's definitely possible but different languages have different strengths. It shouldn't make your brain explode to deal with more than one language and I think you could benefit from a shift in mindset. When I'm in JS world I know l I've gotta let go of performance and security desires (i.e. JS in the browser is a "clear box" and users can fully control it). When I'm in Java I know those things are highly important but also to not stress about "presentation".