Get high-performance immutable data with Limu, a JavaScript library for founders. Based on shallow copy on read and mark modified on write, with 254 GitHub stars.
253 stars14 forksJavaScriptQuality 9/10Updated 4/1/2026100% free Β· open source
What it is
Create high-performance immutable data structures in JavaScript using Limu.
What you can make with it
Applications like a high-traffic e-commerce website that require real-time updates without compromising data integrity.
How it helps
Limu helps by providing fast and efficient data updates, reducing the risk of data corruption and improving overall system performance.
Real use case example
"A founder building a live leaderboard for a sports game app needs to update scores in real-time, so they use Limu to create a fast and immutable data structure for the scores, then deploy it to their production environment."
If you're new
Beginners should pick up Limu when learning JavaScript, as it's an essential library for understanding data structures.
If you're senior
Senior JavaScript developers will reach for Limu when building high-performance applications requiring data immutability.
Common confusion cleared up
Limu's name might be confused with 'limu' meaning seaweed in Hawaiian, but it's derived from 'Library for Immutable data in UI', making it a library focused on data immutability.
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Why we list it on WorkflowStacks: This marketplace includes Limu as a free and open-source library for JavaScript developers.
What it does
Limu provides high-performance immutable data in JavaScript, serving as a lightweight alternative to immer with the same API, utilizing shallow copy on read and mark modified on write mechanisms.
Install / run
npm install limu or yarn add limu
When to use it
β’When you need efficient data management in your JavaScript application
β’When you're looking for a lightweight alternative to immer for state management
β’When performance is critical and you want to avoid unnecessary data copying
Quick start
1Import Limu in your JavaScript file with `import { produce } from 'limu';`
2Create an initial state object, for example, `const initialState = { count: 0 };`
3Use the `produce` function from Limu to create a new state by modifying the initial state, like `const nextState = produce(initialState, draft => { draft.count += 1; });`
4Verify the immutability by checking if the initial state remains unchanged, `console.log(initialState.count); // outputs: 0`
5Experiment with more complex state changes and verify the performance benefits
Ready-to-paste prompt
produce({ a: { b: [1, 2, 3] } }, draft => { draft.a.b.push(4); }); // creates a new state with an updated array without mutating the original state
Heads up: Ensure you are using the correct version of Node.js, as Limu may not be compatible with very old versions, and be aware that Limu is designed to work with the same API as immer, so any existing immer code should work with minimal modifications
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Topics
fast
high-perfomance
immutable
immutablejs
What's inside β free to inspect
No purchase needed
Read the entire source before you build β unlike paid marketplaces that hide it behind a buy button.