Like I said, Windows support is currently middling. I would bet there's some Linux production code in Swift, though not much. But both of these are cultural problems, not technical ones. If Apple said tomorrow, "we're going to go all-in on making Swift a universal programming language", thousands of developers would cheer and jump on-board. The main thing holding it back right now is lack of confidence in its support; people don't want to invest in a new cross-platform codebase that might have its legs cut out from under it in a couple of years.

Swift is much closer to the metal than .NET, and it has very innovative syntax features. It's more analogous to Rust than to C#. .NET is a strong cross-platform ecosystem, but it's silly to say "we don't need any others because this one's good enough". It's not even the strongest one that currently exists - probably the JVM is. It honestly just sounds like you're hating on Apple for the sake of it.

Please don't be snarky or argue in the flamewar style.

https://news.ycombinator.com/newsguidelines.html

Superficially it has a lot in common with JavaScript (really, TypeScript), but like Rust it compiles to a native binary and doesn't need a runtime environment (C# and Java do). Also like Rust, it frees the user from manually managing memory, despite lacking a garbage collector. This combination of features makes both languages very exciting. I'm not aware of any others right now that can claim the same.

I also haven't heard of it being outperformed by Java and C#; do you have a source for that claim?

In microbenchmarks like https://benchmarksgame-team.pages.debian.net/benchmarksgame/... / https://benchmarksgame-team.pages.debian.net/benchmarksgame/... , Swift is mostly equivalent to Java with a few outliers both for/against Swift. Rust outperforms Swift fairly consistently and sometimes quite considerably. Of course, real apps may be different.

The book iOS and macOS Performance Tuning ( https://www.amazon.com/iOS-macOS-Performance-Tuning-Objectiv... ) has pretty damning benchmarks against Swift versus Objective-C even without using any tricky optimizations (not what you originally asked but something to consider). Of course the whole book (written by a former Apple engineer IIRC) is pretty much full of performance gotchas across many Apple frameworks/APIs, but the chapter on Swift was pretty harsh and basically said Swift fails to live up to its name versus Objective-C (at least at the time the book was written).

I think most people think that Swift performs like Rust/C++/C since it doesn't have a garbage collector and imagine ARC is providing relatively free memory management, but it seems Swift performs closer to languages with a garbage collector due to the various design constraints on the language (interoperability with Objective-C, ARC isn't free, and maybe without the explicit lifetime/ownership declarations in the code like Rust, ARC can't be optimized as well).

That's interesting and surprising. I definitely had the perception you described toward the bottom.

I know multiple teams who have Swift in production on Linux servers

Alright, well, don't do that.

Why not? Dive in, the water’s great.

https://vapor.codes

ballsy slogan they got there

yeah their marketing isn't great

Why not?