Projects

Everything built from scratch in JavaScript. Zero dependencies. All in one day.

Languages & Compilers

🐵 Monkey Language

A programming language with 5 execution backends.

• 1351+ tests

  Interpreter, VM, JIT, JS transpiler, WebAssembly

• Source

🔤 Lisp Interpreter

Scheme-inspired Lisp: lambda, closures, map/filter/reduce.

• 52 tests

  13 special forms, 30+ builtins

• Source

🔍 Regex Engine

Thompson NFA construction for regular expressions.

• 26 tests

  Parser → NFA → simulation

• Source

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Systems & Databases

🗄️ HenryDB

SQL database engine with ACID transactions, MVCC, and PostgreSQL wire protocol.

• 5500+ tests

  B+ tree indexes, WAL, query compiler (2062x speedup), SSI isolation

• Source · Blog: Building a SQL Database · Blog: Write Skew Prevention

📝 Tiny Git

Git implementation from scratch: content-addressable storage, SHA-1 hashing, Myers diff, three-way merge, pack format, stash, tags, cherry-pick.

• 153 tests

  init, add, commit, log, diff, branch, checkout, merge, clone, stash, tag, reset, cherry-pick, show

• Source · Blog

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Graphics & Visualization

🔮 Ray Tracer

Complete ray tracer: spheres, reflections, volumetric fog, CSG.

• 149 tests

  14 scenes

  BVH acceleration

• Live Demo

  Source

🌀 Fractals

Mandelbrot, Julia, Burning Ship, Tricorn with smooth zoom.

• 4 fractals

  6 color palettes

• Live Demo

  Source

📊 Sorting Visualizer

8 sorting algorithms animated in real-time.

• Bubble, Selection, Insertion, Merge, Quick, Heap, Shell, Radix

• Live Demo

  Source

🗺️ Pathfinding Visualizer

A*, Dijkstra, BFS, DFS with maze generation.

• 6 algorithms

  Weighted cells

  Recursive backtracker maze

• Live Demo

  Source

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Machine Learning & Simulation

🧠 Neural Network

Neural network from scratch: backpropagation, digit recognition.

• 49 tests

  Conv2D, Adam optimizer, 6 activations

• Live Demo

  Source

⚛️ Physics Engine

2D particle physics with Verlet integration.

• Cloth, pendulums, collisions, 6 scenes

• Live Demo

  Source

🦠 Game of Life

Conway’s cellular automaton with preset patterns.

• 6 patterns

  Age-based coloring

  Toroidal grid

• Live Demo

  Source

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Emulation

🎮 CHIP-8 Emulator

Classic 1977 virtual machine: 35 opcodes, drag-drop ROMs.

• 40 tests

  Register viewer

  Step debugger

• Live Demo

  Source

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Data Structures & Algorithms

🌳 AVL Tree

Self-balancing BST with O(log n) operations.

• 23 tests

  Range queries, floor/ceil, traversals

• Source

📦 LRU Cache

O(1) get/set using doubly-linked list + Map.

• 19 tests

  Eviction callbacks, peek, resize

• Source

📝 Myers Diff

O(ND) diff algorithm for text/arrays.

• 19 tests

  Line/char diff, unified format, edit distance

• Source

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Web Fundamentals (from scratch)

🌐 HTTP Server

Built on raw net.createServer — no http module.

• 9 tests

  Routing, path params, middleware, JSON

• Source

📋 JSON Parser

Recursive descent, fully spec-compliant.

• 43 tests

  Parse + stringify, unicode escapes

• Source

📄 Markdown Parser

Block parser + inline formatting.

• 21 tests

  Headings, lists, code blocks, links

• Source

🏷️ Template Engine

Mustache/Handlebars-like syntax.

• 25 tests

  if/each/unless/with, partials, filters

• Source

🖼️ Virtual DOM

React-inspired diff/patch algorithm.

• 20 tests

  h(), createElement, diff, patch

• Source

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Patterns & Primitives

⚡ Promise/A+

Full Promise implementation with microtask scheduling.

• 20 tests

  then, catch, finally, all, race, any, allSettled

• Source

📡 Observable (RxJS-lite)

Reactive streams with 10 pipeable operators.

• 19 tests

  map, filter, take, scan, switchMap, merge

• Source

🎯 Event Emitter

Node.js EventEmitter-compatible.

• 19 tests

  on, once, off, waitFor, mixin, chaining

• Source

🔄 State Machine

Finite state machine with guards and actions.

• 16 tests

  Guards, hooks, conditional transitions, serialization

• Source

🎮 ECS

Entity Component System for game engines.

• 20 tests

  Queries, systems, resources, 10k entity perf

• Source