# Bonsai by Jane Street

27 Hacker News commenters recommended Bonsai by Jane Street and 3 criticized it, November 2025 to November 2026. It was recommended in 8 of 13 months; owners who said how long report a median of 10 years (3 owners). It meets the Hacker Approved badge rule.

**Verdict:** Free OCaml UI library and voxel engine people praise for clean, from-scratch code and fun incremental rendering; critics find its look dated and unpolished.

## Why people recommend it

- Impressive voxel engine results (4 comments): "Wow, unbelievably cool. Good luck with the new game using the engine" ([source](https://news.ycombinator.com/item?id=49691050)) "it's getting pretty close to being shadertoy for voxels" ([source](https://news.ycombinator.com/item?id=45870938)) "That scale and view-distance..wow!! Brilliant work.." ([source](https://news.ycombinator.com/item?id=49693344))
- Readable source, few dependencies (2 comments): "The docs are a bit sparing but if you read the source its pretty cool to see how they did this." ([source](https://news.ycombinator.com/item?id=49159480)) "It's written completely from scratch, and depends on nearly nothing external." ([source](https://news.ycombinator.com/item?id=49926308))
- Useful editor and Blender rendering (2 comments): "Probably the most interesting thing about it at the moment is the editor." ([source](https://news.ycombinator.com/item?id=49690404)) "Strong plus is that you can render views of the finished room in Blender." ([source](https://news.ycombinator.com/item?id=45979503))
- Screenshots look awesome (2 comments): "the look and aesthetic of some of your screenshots is awesome" ([source](https://news.ycombinator.com/item?id=46296875)) "it appears that this person totally nailed it" ([source](https://news.ycombinator.com/item?id=46297258))

## What people warn about

- Dated, unpolished look (3 comments): "Everything looks like it's straight out of the 1990s." ([source](https://news.ycombinator.com/item?id=49154490)) "all the UI elements look extremely unpolished to me" ([source](https://news.ycombinator.com/item?id=49155639)) "to me it's extremely ugly" ([source](https://news.ycombinator.com/item?id=49154525))
- Verbose, reinvents existing tools (2 comments): "ridiculously verbose their library is compared to React/Vue" ([source](https://news.ycombinator.com/item?id=49157968)) "looks like it's reinventing the wheels" ([source](https://news.ycombinator.com/item?id=49153558))

## Alternatives hackers recommend

- [MicroUI by rxi](https://hackerapproved.com/p/microui.md): 13 recommend
- [Reagent](https://hackerapproved.com/p/reagent.md): 5 recommend

## Cite as

Hacker Approved, "Bonsai by Jane Street", https://hackerapproved.com/p/bonsai/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).