{"slug": "jolt", "name": "Jolt", "category": "dev-libs", "category_name": "Libraries and frameworks", "description": "", "recommenders": 5, "commenters": 11, "warners": 2, "score": 3.589, "rising": -0.31, "first": "2026-03-24", "latest": "2026-10-09", "why": "Glad to see some healthy physics simulation options, next to Jolt, PhysX and https://github.com/newton-physics/newton", "why_is_quote": true, "has_verdict": false, "sentiment": {"recommend": 5, "neutral": 2, "compare": 2, "warn": 2}, "spark": [0, 0, 0, 0, 2, 0, 0, 0, 2, 1, 0, 0], "listed": true, "loved": [], "caveat": "", "short_quote": "Glad to see some healthy physics simulation options, next to Jolt, PhysX and https://github.com/newton-physics/newton", "kind": "", "icon": true, "domain": null, "github_repo": "github.com/jrouwe/joltphysics", "official_url": "https://github.com/jrouwe/joltphysics", "pricing": "", "aliases": ["Jolt"], "verdict": null, "praise": [{"label": "", "summary": "", "quotes": [{"id": 800472146, "item_id": 50029509, "url": "https://news.ycombinator.com/item?id=50029509", "by": "yogthos", "date": "2026-10-10", "stance": "recommend", "quote": "Jolt solved this problem for me completely.", "excerpt": "I have yet to have a good experience with any JVM based app on the desktop with or without Clojure. Take a look at something like in IntelliJ as an example. It doesn't have a Clojure runtime, and it takes forever to start using gigs of memory. Like you said, it makes Electron apps look lean. I ended up switching to using VSCode because it just runs a lot better and uses less memory. And when it comes to Clojure speci", "context": "", "use_case": "fast-starting Clojure apps", "switched_from": "", "story": "Clojure in the age of language models"}, {"id": 788389648, "item_id": 49274353, "url": "https://news.ycombinator.com/item?id=49274353", "by": "JerboaScheme", "date": "2026-08-12", "stance": "recommend", "quote": "Jolt is amazing work.", "excerpt": "Chez Scheme is highly underrated! Jolt is amazing work. I also have been using it for Jerboa, a Gerbil Scheme compatible language. https://jerboa.sh 8,820,174 lines of 100% vibe coded code.", "context": "", "use_case": "", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 780110080, "item_id": 48756880, "url": "https://news.ycombinator.com/item?id=48756880", "by": "erwincoumans", "date": "2026-07-01", "stance": "recommend", "quote": "Glad to see some healthy physics simulation options, next to Jolt, PhysX and https://github.com/newton-physics/newton", "excerpt": "Great to finally see Box3D released! Glad to see some healthy physics simulation options, next to Jolt, PhysX and https://github.com/newton-physics/newton (using MuJoCo Warp, which I've been pushing at NVIDIA). Bullet Physics author.", "context": "Bullet Physics author", "use_case": "physics simulation", "switched_from": "", "story": "Announcing Box3D :: Box2D"}, {"id": 779990128, "item_id": 48749383, "url": "https://news.ycombinator.com/item?id=48749383", "by": "dom96", "date": "2026-07-01", "stance": "recommend", "quote": "So far Jolt is working pretty well", "excerpt": "Funny to see this just a few days after I\u2019ve started building a Tron-like 3D game for the browser using Jolt[1]. So far Jolt is working pretty well but I\u2019ll certainly be taking a look at this. 1 - I\u2019ve been sitting on this domain for years: https://lightcycles.io", "context": "", "use_case": "3D physics in browser game", "switched_from": "", "story": "Announcing Box3D :: Box2D"}, {"id": 760115776, "item_id": 47507236, "url": "https://news.ycombinator.com/item?id=47507236", "by": "ux266478", "date": "2026-03-24", "stance": "recommend", "quote": "can be extremely high quality, like Jolt", "excerpt": "> Today the options are either free and open source (which can be extremely high quality, like Jolt: https://github.com/jrouwe/JoltPhysics) I did mention this was changing in particular with physics engines. That being said, proprietary dependencies still reign supreme in places like audio engines. Something like OpenAL isn't really a replacement for FMOD or Wwise. I know those off-the-shelf engines roll their own re", "context": "", "use_case": "physics engine", "switched_from": "", "story": "Testing the Swift C compatibility with Raylib (+WASM)"}]}], "caveats": [{"label": "", "summary": "", "quotes": [{"id": 788239632, "item_id": 49264977, "url": "https://news.ycombinator.com/item?id=49264977", "by": "YorickPeterse", "date": "2026-08-11", "stance": "warn", "quote": "Competent or not, slop is still slop.", "excerpt": "Competent or not, slop is still slop. The website in particular uses the exact same copy-paste layout/style produced by LLMs and used by pretty much every slop project out there. One very quick \"slop or not?\" test is to see if em dashes are used in the source code where they literally never make sense. It's not a great test, but it's one that consistently turns out to be good enough. The results should speak for them", "context": "", "use_case": "", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 788224960, "item_id": 49264060, "url": "https://news.ycombinator.com/item?id=49264060", "by": "davexunit", "date": "2026-08-11", "stance": "warn", "quote": "This appears to be vibecoded but not disclosed as such.", "excerpt": "This appears to be vibecoded but not disclosed as such. 2k commits from a single author starting from June 1st with really long commit messages and source code comments. The GitHub org has 19 additional projects that are all recently created. edit: Yup, found a very long blog post that says it's made with LLMs near the end https://yogthos.net/posts/2026-07-02-jolt.html", "context": "", "use_case": "", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}]}], "who": [{"by": "erwincoumans", "context": "Bullet Physics author", "url": "https://news.ycombinator.com/item?id=48756880", "date": "2026-07-01"}], "tags": [], "use_cases": ["clojure compiler", "fast-starting clojure apps", "clojure compiler on chez scheme", "physics simulation", "3d physics in browser game", "physics engine"], "compared": [{"slug": "box3d", "name": "Box3D", "co": 2, "switched_from": 0, "switched_to": 0}], "makers": [{"id": 788222752, "item_id": 49263922, "url": "https://news.ycombinator.com/item?id=49263922", "by": "yogthos", "date": "2026-08-11", "stance": "recommend", "quote": "Definitely excited with the progress so far.", "excerpt": "Hi, thanks, glad to hear you enjoy my other work! :) And yes, you absolutely can drop both down to Scheme and do FFI to drive native libs as well https://jolt-lang.github.io/docs/host-interop.html https://jolt-lang.github.io/docs/native-interop.html I actually leverage this myself in libraries, I ended up writing a Java time layer to support tick here, and I decided to make it a library since I wanted the core execut", "context": "", "use_case": "Clojure compiler", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 788216896, "item_id": 49263556, "url": "https://news.ycombinator.com/item?id=49263556", "by": "yogthos", "date": "2026-08-11", "stance": "recommend", "quote": "Jolt basically aims to be a drop in JVM replacement for running existing Clojure code.", "excerpt": "I have a slightly different goal from Jank because my goal is to provide a runtime that supports existing Clojure libraries. I've spent the time to map out Java standard library APIs that popular libraries use and to create shims on top of Chez that allows them to run seamlessly. You can see a list of libraries that are fully tested and officially supported here. https://jolt-lang.github.io/docs/libraries.html On top", "context": "", "use_case": "Clojure runtime on Chez Scheme", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 788181872, "item_id": 49261367, "url": "https://news.ycombinator.com/item?id=49261367", "by": "yogthos", "date": "2026-08-11", "stance": "recommend", "quote": "I recently factored out a portable Scheme layer and got Jolt to compile against Gambit as a backend.", "excerpt": "Thanks, and I have good news on that front actually. I recently factored out a portable Scheme layer and got Jolt to compile against Gambit as a backend. And given that Racket is basically an extension of Chez, it should be trivial to build against it now. I wrote up a post on how this works here https://yogthos.net/posts/2026-08-07-portable-jolt.html", "context": "", "use_case": "Clojure compiler", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 787758274, "item_id": 49234892, "url": "https://news.ycombinator.com/item?id=49234892", "by": "mercutio93", "date": "2026-08-09", "stance": "neutral", "quote": "As for Jolt this work is more expirimental truth be told I started it this year", "excerpt": "Hey dude... honestly speaking im not really doing this for traction. I use the0 trading platform day to day implement algorithmic trading strategies that run 24/7 365 some of them are conventional trading strategies and others are portfolio rebalancers. the0s a project that come a long way Ive been working on it for a few years now. The core architecture of it is complete. It more just implementing things I feel need", "context": "", "use_case": "decentralized social protocol", "switched_from": "", "story": "Show HN: Vibez \u2013 Open-Source Rust Based Digital Audio Workstation (DAW)"}], "threads": [{"url": "https://news.ycombinator.com/item?id=49223965", "title": "Jolt: Clojure compiler implemented with Chez Scheme", "mentions": 9}, {"url": "https://news.ycombinator.com/item?id=50002215", "title": "Clojure in the age of language models", "mentions": 2}, {"url": "https://news.ycombinator.com/item?id=48745445", "title": "Announcing Box3D :: Box2D", "mentions": 2}, {"url": "https://news.ycombinator.com/item?id=47477525", "title": "Testing the Swift C compatibility with Raylib (+WASM)", "mentions": 2}, {"url": "https://news.ycombinator.com/item?id=49232369", "title": "Show HN: Vibez \u2013 Open-Source Rust Based Digital Audio Workstation (DAW)", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=47790041", "title": "I learned Unity the wrong way", "mentions": 1}], "sentiment_by_month": {"2025-11": {}, "2025-12": {}, "2026-01": {}, "2026-02": {}, "2026-03": {"recommend": 2}, "2026-04": {"compare": 1}, "2026-05": {}, "2026-06": {}, "2026-07": {"recommend": 2}, "2026-08": {"compare": 1, "warn": 2, "neutral": 1, "recommend": 1}, "2026-09": {}, "2026-10": {"neutral": 1}}, "quotes": [{"id": 800472146, "item_id": 50029509, "url": "https://news.ycombinator.com/item?id=50029509", "by": "yogthos", "date": "2026-10-10", "stance": "recommend", "quote": "Jolt solved this problem for me completely.", "excerpt": "I have yet to have a good experience with any JVM based app on the desktop with or without Clojure. Take a look at something like in IntelliJ as an example. It doesn't have a Clojure runtime, and it takes forever to start using gigs of memory. Like you said, it makes Electron apps look lean. I ended up switching to using VSCode because it just runs a lot better and uses less memory. And when it comes to Clojure speci", "context": "", "use_case": "fast-starting Clojure apps", "switched_from": "", "story": "Clojure in the age of language models"}, {"id": 800286944, "item_id": 50017934, "url": "https://news.ycombinator.com/item?id=50017934", "by": "pjmlp", "date": "2026-10-09", "stance": "neutral", "quote": "great to have Jolt as an option as well", "excerpt": "> There are, however, a few drawbacks to the Java virtual machine, which Clojure traditionally runs on. From my experience, many developers, fairly or not, have an issue with requiring the JVM, and shy away from Clojure because of startup time, a somewhat heavyweight runtime, and perceived bootstrapping complexity. This used to be discussed in the past and it has been proven that the culprit is the clojure implementa", "context": "", "use_case": "", "switched_from": "", "story": "Clojure in the age of language models"}, {"id": 788389648, "item_id": 49274353, "url": "https://news.ycombinator.com/item?id=49274353", "by": "JerboaScheme", "date": "2026-08-12", "stance": "recommend", "quote": "Jolt is amazing work.", "excerpt": "Chez Scheme is highly underrated! Jolt is amazing work. I also have been using it for Jerboa, a Gerbil Scheme compatible language. https://jerboa.sh 8,820,174 lines of 100% vibe coded code.", "context": "", "use_case": "", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 788365936, "item_id": 49272871, "url": "https://news.ycombinator.com/item?id=49272871", "by": "yogthos", "date": "2026-08-12", "stance": "neutral", "quote": "Jolt actually does have both Scheme interop and FFI", "excerpt": "Jolt actually does have both Scheme interop and FFI https://jolt-lang.net/docs/host-interop.html and it is possible to make .so libraries with Jolt as well right now", "context": "", "use_case": "Clojure compiler", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 788239632, "item_id": 49264977, "url": "https://news.ycombinator.com/item?id=49264977", "by": "YorickPeterse", "date": "2026-08-11", "stance": "warn", "quote": "Competent or not, slop is still slop.", "excerpt": "Competent or not, slop is still slop. The website in particular uses the exact same copy-paste layout/style produced by LLMs and used by pretty much every slop project out there. One very quick \"slop or not?\" test is to see if em dashes are used in the source code where they literally never make sense. It's not a great test, but it's one that consistently turns out to be good enough. The results should speak for them", "context": "", "use_case": "", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 788236817, "item_id": 49264801, "url": "https://news.ycombinator.com/item?id=49264801", "by": "Jeaye", "date": "2026-08-11", "stance": "neutral", "quote": "", "excerpt": "Protocols, records, and the like will be implemented in jank. They haven't been prioritized for two reasons. Firstly, historically, jank had a closed object model for performance, which I have blogged about here: https://jank-lang.org/blog/2023-07-08-object-model/ Over the past few years, I've been spending hammock time to find a solution to this to re-open the object model efficiently. I came up with a design this y", "context": "", "use_case": "Clojure compiler", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 788224960, "item_id": 49264060, "url": "https://news.ycombinator.com/item?id=49264060", "by": "davexunit", "date": "2026-08-11", "stance": "warn", "quote": "This appears to be vibecoded but not disclosed as such.", "excerpt": "This appears to be vibecoded but not disclosed as such. 2k commits from a single author starting from June 1st with really long commit messages and source code comments. The GitHub org has 19 additional projects that are all recently created. edit: Yup, found a very long blog post that says it's made with LLMs near the end https://yogthos.net/posts/2026-07-02-jolt.html", "context": "", "use_case": "", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 788194385, "item_id": 49262149, "url": "https://news.ycombinator.com/item?id=49262149", "by": "phtrivier", "date": "2026-08-11", "stance": "compare", "quote": "How much \"production ready\" / \"battle tested\" would this be ?", "excerpt": "How much does this overlap / complements something like jank ? [1] How much \"production ready\" / \"battle tested\" would this be ? (Not to start a flame war, I'm genuinely curious about the differences.) [1] https://github.com/jank-lang/jank", "context": "", "use_case": "Clojure compiler on Chez Scheme", "switched_from": "", "story": "Jolt: Clojure compiler implemented with Chez Scheme"}, {"id": 780110080, "item_id": 48756880, "url": "https://news.ycombinator.com/item?id=48756880", "by": "erwincoumans", "date": "2026-07-01", "stance": "recommend", "quote": "Glad to see some healthy physics simulation options, next to Jolt, PhysX and https://github.com/newton-physics/newton", "excerpt": "Great to finally see Box3D released! Glad to see some healthy physics simulation options, next to Jolt, PhysX and https://github.com/newton-physics/newton (using MuJoCo Warp, which I've been pushing at NVIDIA). Bullet Physics author.", "context": "Bullet Physics author", "use_case": "physics simulation", "switched_from": "", "story": "Announcing Box3D :: Box2D"}, {"id": 779990128, "item_id": 48749383, "url": "https://news.ycombinator.com/item?id=48749383", "by": "dom96", "date": "2026-07-01", "stance": "recommend", "quote": "So far Jolt is working pretty well", "excerpt": "Funny to see this just a few days after I\u2019ve started building a Tron-like 3D game for the browser using Jolt[1]. So far Jolt is working pretty well but I\u2019ll certainly be taking a look at this. 1 - I\u2019ve been sitting on this domain for years: https://lightcycles.io", "context": "", "use_case": "3D physics in browser game", "switched_from": "", "story": "Announcing Box3D :: Box2D"}, {"id": 765506418, "item_id": 47844151, "url": "https://news.ycombinator.com/item?id=47844151", "by": "vivzkestrel", "date": "2026-04-20", "stance": "compare", "quote": "There seems to be a library called jolt which claims to handle physics well", "excerpt": "- i have started brushing my c++ and learning 3d math for now - i am interested to know for starters what does the 10000 ft landscape look like - what are the major steps involved? - what have I tried? I spent a lot of time looking into what kind of libraries exist. Rust has something called bevy which I would not touch given it is new and I dont want to work with double unknowns - C++ has a library called raylib tha", "context": "", "use_case": "", "switched_from": "", "story": "I learned Unity the wrong way"}, {"id": 760115776, "item_id": 47507236, "url": "https://news.ycombinator.com/item?id=47507236", "by": "ux266478", "date": "2026-03-24", "stance": "recommend", "quote": "can be extremely high quality, like Jolt", "excerpt": "> Today the options are either free and open source (which can be extremely high quality, like Jolt: https://github.com/jrouwe/JoltPhysics) I did mention this was changing in particular with physics engines. That being said, proprietary dependencies still reign supreme in places like audio engines. Something like OpenAL isn't really a replacement for FMOD or Wwise. I know those off-the-shelf engines roll their own re", "context": "", "use_case": "physics engine", "switched_from": "", "story": "Testing the Swift C compatibility with Raylib (+WASM)"}, {"id": 760111394, "item_id": 47506962, "url": "https://news.ycombinator.com/item?id=47506962", "by": "flohofwoe", "date": "2026-03-24", "stance": "recommend", "quote": "which can be extremely high quality, like Jolt", "excerpt": "Pathfinding middleware has traditionally been a thing though, e.g. apart from the mentioned ReCast (which is the popular free solution) the commercial counterpart was PathEngine (looks like they are even still around: https://pathengine.com/overview/). If you need to do efficient path finding on random triangle geometry (as opposed to running A* on simple quad or hex grids) it quickly gets tricky. What has undeniably", "context": "", "use_case": "", "switched_from": "", "story": "Testing the Swift C compatibility with Raylib (+WASM)"}]}