why do we even need the rebuilt? idea is already opensource[0].
In the benchmark[1] the cpu, memory and quit time (!) are compared, but does it makes any sense without feature parity?
"rebuilt in Rust"
looks inside
60% Typescript
Yeah, didn't think so...
From the promo video:
> completion from language servers
That's exactly the thing that I like about idea: It's better than that.
Calling it "OpenIDEA" is a bit misleading. IntellijIDEA is free and open source (Apache 2.0) since 2009. Paid subscription basically gives you extra plugins. And as others pointed out, saying that it was rebuilt in Rust is at least as much misleading: the code processing is still standalone LSP processes, frontend is WebView with typescript, only Tauri glue code is Rust. And that in turn makes me extremely skeptical about claimed memory usage! Consider that you must compare idea.exe against combo of WebView (on windows: chromium edge) + LSP (for Java, likely Eclipse LSP, at least that's what VSCode traditionally uses for Java). Is it realistic to fit that in claimed 169 MB?
Interesting project. It seems it uses CodeMirror [1] in the Tauri frontend (60% of total code is typescript), but uses rust in the backend (30%). Surprising to see that Tauri is apparently good enough for the three platforms it needs to support (or it uses a lot of hacks, I don't know). The advertised memory reduction is remarkable as I expected a full web view to be a bit memory heavy. Not sure how this IDE keeps up with large documents or a lot of opened views though.
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1. The editor implementation is here: <https://github.com/l0ng-ai/openidea/blob/main/src/editor/cor...>
2025 was all about 'Rust' on HN and 2026 is all about 'rebuilding everything in Rust'. Comical on one level and yet intriguing.
So that I understand...
I guess the logic here is: If I love this project, I should renew my JetBrains subscription...so that they can keep having money to fix bugs in their IDE...so that you can keep reverse engineering it?
Am I seeing this right?
There is a (Bertrand Russell?) quote about axiomatic approach having the same advantages as theft compared to honest work.
I'm not sure exactly why this came to mind. Vibes?
Eclipse was an ide that needed a supercomputer to run on an early version of Java when it first came out.
It was interesting, but sluggish.
Jetbrains took advantage of it for profit and eventually adobe'd the business model, although granted they made a lot of improvements for various languages.
I have no pity for companies who made money off open source and lose it the same way. But this looks like a fight between fighters past their prime.
Where Rust scores over Go is not so much on the speed but memory usage. As memory is becoming expensive (and likely to stay for sometime), the appeal for Rust increases.
The large disk space usage for Rust is much more solvable than speed-up in Rust compilation as long as crate remains the lowest compilation unit.
Barring this, even for AI based development Golang is much better language. But Rust's long term payoff is too good at this point.
The only value adding vibe coded software I've used so far has been clones of existing software that can then be used for free since now it's in a legal greyzone and you can pretend it's not piracy...all thanks to subsidized subscriptions enabled by companies who are in part the publishers of the software that is being cloned. What a time to be alive...
Looks like Qt Creator after all.
I bet it's a lot of fun being a Rust programmer / coder.
They should’ve copied the classic UI.
So it’s main selling point is being IDEA clone…but in Rust?
Just use Zed.
How did Hacker News become the place where you announce a hack and all the comments are like "I don't like this because I feel it might be in a legal gray area"?
Sorry if I'm wrong, but does people pay for JetBrains product subscriptions not for a continuously maintained IDE, but for a Rust-based IDE?
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Uses Typescript for the most part, not much better than Electron stuff, cannot use the InteliJ plugins powered by the JVM, it is vibe coded, no thanks.