Kivi project is all about winning benchmarks, I don't think that many of its benchmark specific "optimizations" are useful in real projects. It doesn't have really important feature for building reusable components, it is impossible to return Components as a root node for another component (HOCs that just wrap another components). This tradeoff was made to implement efficient event delegation because we need to map 1-1 DOM Nodes with Component instances. Its API is quite ugly, all API decisions were made to squeeze out the latest bits of performance, right now profiler reports are mostly dominated by "native" code.

This project was an inspiration for many other libraries, if you want to learn how to build a really fast web UI library, take a look at its source code. Code base are quite ugly, but most of the time it was made this way to win benchmarks.

I don't think that tradeoffs that were made to win benchmarks are worth it, so I've created ivi library, it is using all the good parts of the kivi library, and is all about developer productivity without any benchmark specific optimizations, it won't be able to win all benchmarks, but it really doesn't matter, because winning benchmarks is not just optimizations in a library, benchmark implementations for the fastest libraries are implemented in non-idiomatic ways, and libraries are mostly optimized for this non-idiomatic code that nobody would ever write. Some benchmark specific optimizations are actually would hurt real applications, I've tried to stay away from them in kivi, but I've noticed that other developers are okay with that and just want to get better numbers in benchmarks.

ivi library is optimized for idiomatic code. It also fixes some long-standing issues that are common to all React-like libraries, like completely broken Contexts.

Example

import {ComponentDescriptor, injectComponent} from "kivi";

const Main = new ComponentDescriptor()
  .update((c, props) => {
     c.sync(c.createVRoot().child(`Hello ${props.name}`));
  });

injectComponent(Main, document.body, {name: "World"});

Documentation

• Getting Started
• Basics
  • Components
  • Virtual DOM
• Advanced
  • Element Descriptor
  • Scheduler
  • Components
  • Virtual DOM
  • Events
  • Reactive Bindings
• Experimental
  • Incremental Rendering

Examples

• Intro
• Stateful Component
• Canvas
• TodoMVC

Performance

Kivi has one of the fastest Virtual DOM implementations, it was designed from the ground up with high performance in mind.

Benchmarks:

• uibench
• dbmonster
• 10k components