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?
Correction: Rust is more than just Tauri glue code (https://github.com/l0ng-ai/openidea/issues/568#issuecomment-...). But considering that in an IDE the two performance critical parts are code processing (LSP) and frontend, I wonder how much benefit can you really get by making everything except of them in Rust.
Overall I actually agree that VSCode has proven that making responsive web based frontends is absolutely viable for the IDE, if you accept startup latency, size and memory use of CEF / Electron. And on Windows and macOS, system WebView may be sufficiently compatible (not on Linux anytime soon!), and they significantly amortize all of those downsides.
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.
But maybe a Lindy effect measuring effort rather than time (as a signal of commitment). Git commits no longer mean effort since the computer can just make commits on its own.
Still, one day I expect to see a fully vibe coded project and to see that the guy has been maintaining it for ten years. That will probably give me a different impression.
We just don't know yet which of today's projects will survive, and which will be rapidly abandoned.
>but does it makes any sense without feature parity?
The entire project makes no sense. Names itself Open when IDEA is already open, says built in Rust when 60% is TS, says it's native app when it's a web app with a native connection, clueless benchmarks, made by vibe coders who don't even use/need an IDE, ...
Yeah, it's a Tauri app, which makes the claim in the README about it being a native app also rather a lie.
Did Tauri ever figure out how to run performantly on Linux, or are they still using webkit2gtk? They were looking at integrating Servo last time I checked, but I have no clue how far they've progressed with that since.
The author's comment appears AI generated (or at very least heavily edited) and (imo) should be taken with a grain of salt. Very probable they don't know or/and thought of any of the usability/maintenance/performance considerations/costs mentioned within and they just blindly accepted whatever Claude generated.
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.
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?
I know this exact comment is probably becoming tedious on HN, but it's very rare that a tool I pay for is so bad I'll jump ship for 0.1.0 alpha if a clone.
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...
If you do a lookup at WIPO brands database you can find "intellij" and "intellij idea" owned by Jetbrains s.r.o. but not "idea" alone.
Based on this only a judge can decide if it is close enough to be an infringement and could misled customers. Given the readme days eplicitely says it is not the same IDE as Intellij IDEA I would say it would be hard to convince someone customers are misled.
Also try Lapce! In my experience somehow starts noticably faster even than Zed. Also implemented in Rust but different GUI approach. Both support LSPs.
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"?
It didn’t, there are a few (shallow) replies which are downvoted to the bottom of the page. But perhaps when you looked at the page these comments were new and you were just unlucky.
The discussion about IP with these reverse engineered products in itself is interesting, although a bit repetitive with new clones every day.
The whole build in rust nonsense has gone too far. It's a great systems language, but it isn't great for apps e.g.: https://github.com/shai-almog/cn1-wordprocessor/
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?
Correction: Rust is more than just Tauri glue code (https://github.com/l0ng-ai/openidea/issues/568#issuecomment-...). But considering that in an IDE the two performance critical parts are code processing (LSP) and frontend, I wonder how much benefit can you really get by making everything except of them in Rust.
Overall I actually agree that VSCode has proven that making responsive web based frontends is absolutely viable for the IDE, if you accept startup latency, size and memory use of CEF / Electron. And on Windows and macOS, system WebView may be sufficiently compatible (not on Linux anytime soon!), and they significantly amortize all of those downsides.
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.
>vibe coded, no thanks
I hear this a lot, the argument usually being "they didn't care to put effort into it, so it probably won't be maintained.
That's a reasonable assumption. It's basically the Lindy effect: The longer something has existed, the longer it probably will.
https://en.wikipedia.org/wiki/Lindy_effect
But maybe a Lindy effect measuring effort rather than time (as a signal of commitment). Git commits no longer mean effort since the computer can just make commits on its own.
Still, one day I expect to see a fully vibe coded project and to see that the guy has been maintaining it for ten years. That will probably give me a different impression.
We just don't know yet which of today's projects will survive, and which will be rapidly abandoned.
It is the same measurement as those AI written Readme files, blog posts and articles.
It is still the output of a replicator machine, regardless of text, images, video or code.
I think everyone knows.
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?
[0]: https://github.com/jetbrains/intellij-community
[1]: https://github.com/l0ng-ai/openidea#benchmark
>but does it makes any sense without feature parity?
The entire project makes no sense. Names itself Open when IDEA is already open, says built in Rust when 60% is TS, says it's native app when it's a web app with a native connection, clueless benchmarks, made by vibe coders who don't even use/need an IDE, ...
It does, because one might not use all the features while still paying performance cost.
"rebuilt in Rust"
looks inside
60% Typescript
Yeah, didn't think so...
Yeah, it's a Tauri app, which makes the claim in the README about it being a native app also rather a lie.
Did Tauri ever figure out how to run performantly on Linux, or are they still using webkit2gtk? They were looking at integrating Servo last time I checked, but I have no clue how far they've progressed with that since.
It's still webkit2gtk. A chromium version is in the works but it seems to use x11 under the hood..? So still not great.
I dont think the author knows what either of those things are. The whole thing is vibed.
Which is ironic. Why would a vibe coder need an IDE anyway?
This ticket tries to explain it: https://github.com/l0ng-ai/openidea/issues/568
Building consistent frontends for all platforms isn’t easy in rust, so they use web standards for that.
The author's comment appears AI generated (or at very least heavily edited) and (imo) should be taken with a grain of salt. Very probable they don't know or/and thought of any of the usability/maintenance/performance considerations/costs mentioned within and they just blindly accepted whatever Claude generated.
So maybe Rust isn't the best tool for the job.
"we have Rust at home"
Rust at home:
Things like these make me question the provided benchmarks too
The comparisons of speed and memory usage only make sense if there's feature parity.
From the promo video:
> completion from language servers
That's exactly the thing that I like about idea: It's better than that.
That is exactly what I value in IDEA. Language server integration offers the same level of completion and functionality in all other editors, too.
IDEA is much smarter than what a language server alone offers.
It’s also presumably where some of the memory is going
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.
___
1. The editor implementation is here: <https://github.com/l0ng-ai/openidea/blob/main/src/editor/cor...>
Tauri on Linux is horrible, but that's due to the poor state of WebKitGTK than Tauris fault.
vibed a tauri app the other day ~60MB RAM usage. quite happy with that!
How is that even possible, browser in 60M? Or are you not counting the new web process you get started together with your app?
This is fantastic. The Jetbrains Java fetish has always crippled these otherwise good tools.
2025 was all about 'Rust' on HN and 2026 is all about 'rebuilding everything in Rust'. Comical on one level and yet intriguing.
The low-effort metacommentary on what all of HN is supposedly doing or saying is what 2026 HN is really about.
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?
The Readme has that first pass vibe coded feel.
Which isn't the vibe I want from my editor.
I know this exact comment is probably becoming tedious on HN, but it's very rare that a tool I pay for is so bad I'll jump ship for 0.1.0 alpha if a clone.
Long story short, I'm keeping my sub.
Yes, you still have to pay Jetbrains to release their prompt.
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.
I rather go with vibe coded machine language, YOLO! /s
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...
They should’ve copied the classic UI.
Looks like Qt Creator after all.
I bet it's a lot of fun being a Rust programmer / coder.
How is this not a trademark infringement?
well, it is not called intellij idea for a start.
If you do a lookup at WIPO brands database you can find "intellij" and "intellij idea" owned by Jetbrains s.r.o. but not "idea" alone.
Based on this only a judge can decide if it is close enough to be an infringement and could misled customers. Given the readme days eplicitely says it is not the same IDE as Intellij IDEA I would say it would be hard to convince someone customers are misled.
So it’s main selling point is being IDEA clone…but in Rust?
How many tokens did you burn on this?
Just use Zed.
Also try Lapce! In my experience somehow starts noticably faster even than Zed. Also implemented in Rust but different GUI approach. Both support LSPs.
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"?
> announce a hack
Since when cloning an open source project became a "hack" ?
Since HN has been endowed with a de facto Slop HN: ... category
It didn’t, there are a few (shallow) replies which are downvoted to the bottom of the page. But perhaps when you looked at the page these comments were new and you were just unlucky.
The discussion about IP with these reverse engineered products in itself is interesting, although a bit repetitive with new clones every day.
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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