A custom cop collection of working toolkits.

Pure-Ruby MIDI library for messages, ports, SMF I/O, middleware, network MIDI, and MIDI 2.0 UMP.

A WebUSB-style API to Ruby applications.

A tiny Ruby JIT compiler for learning how bytecode VMs, interpreters, and x86-64 native code generation work.

A three.js-like scene graph and WebGPU renderer for Ruby, with PBR, glTF, animation, shadows, and offscreen rendering.

RuboCop runner for Ruby code embedded in Slim.

Evidence-based test suite adequacy analysis for Ruby, combining coverage, mutation testing, checked coverage, redundancy detection, and test-smell heuristics.

Fast JSON Schema validator for Ruby.

象算木之法，以字畫示整數加減之程

A RuboCop extension focused on enforcing RSpec. A place where no one is officially employed, but where useful cops can gather.

Headless terminal emulator library for Ruby.

Detect RSpec examples that leak global state, resources, time travel, randomness, or filesystem changes.

Detect ignored ActiveRecord rollbacks in joined nested transactions

Dependency-free Ruby library for loading and writing glTF 2.0 and GLB with GPU-ready packed accessors.

🛤️ A tiny Ruby+SVG library for drawing railroad syntax diagrams like JSON.org.

Detect PostgreSQL and MySQL session-state leaks in Active Record connection pools.

Parselly is a module providing a simple way to parse and extract data from a css selector 🌿

Hybrid dead-code detection for Ruby projects.

Ruby FFI bindings for RtMidi with Ruby-idiomatic MIDI input/output, typed messages, and low-level C API access.

A Pure Ruby Markdown linter and formatter.

A visual editor for Lrama grammar files (.y files) powered by Ruby Wasm.

Strict JSON5 1.0.0 parser in Pure Ruby with generated grammar, diagnostics, limits, and lossless Document mode.

Generated Ruby bindings for Dear ImGui with an idiomatic API, exception-safe DSL, GLFW/SDL3/OpenGL/WebGPU backends, and ImPlot.

Ruby bindings for HarfBuzz text shaping engine

A programming language compiler using "Grongi language," the language of the Gurongi tribe from Kamen Rider Kuuga (Masked Rider Kuuga).

A cli that highlights gems you can likely remove from a Ruby project's Gemfile.

A small Ruby gem for reading large JSON array, NDJSON, and CSV inputs one record at a time

A Ruby audio synthesis library with a flexible node graph, oscillator and synth variants, effects, transport/event scheduling, sample playback, analysis utilities, offline rendering, and an optional PortAudio-backed realtime context.

Causal profiling toolkit for Ruby that estimates which lines or waits would actually improve throughput or latency.

Ruby FFI bindings for robust Clipper2 polygon clipping, offsets, and GPU-ready triangulation.

Web Bluetooth API-style BLE interface for Ruby.

Ruby bindings for WebGPU via wgpu-native.

A pure Ruby audio processing gem focused on ergonomic APIs and immutable audio transforms.

Ruby FFI bindings for libusb 1.0.

A minimal LLM implemented in pure Ruby

A slim file to minify embedded code.

Battery-included monitoring and alerting for Sidekiq

Japanese seasonal and lunisolar calendar calculations in Ruby: 24 solar terms, 72 microseasons, observances, new moons, and date conversion.

A pure Ruby LALR(1) parser generator. You define a grammar with a Ruby DSL, and Rusa generates a standalone Ruby parser with no runtime gem dependency.

A RuboCop Extension Template.

Runtime risky-test detection for RSpec: reports tests with no expectations or unexpected output.

Detect, record, and classify flaky RSpec failures with normalized signatures, isolated reruns, and CI-friendly reports.

Catch Active Record objects whose database writes rolled back while their in-memory state stayed changed.

Ruby bindings for RenderDoc's in-application API, with programmatic GPU frame capture and RSpec integration.

Educational compiler backend targeting C through printf %n, with Brainfuck and conservative LLVM IR subset frontends.

A small 2D game engine for PicoRuby and CRuby-based POSIX development.

Simple YAML Frontmatter Parser

lxdb (LLeXtreme DeBugger) is a powerful, pwndbg-style debugger for Ruby built on top of lldb-ruby.

Frame-level Ruby bindings for FFmpeg video and audio encoding/decoding without subprocesses.

A terminal slide rule simulator for Ruby, with interactive sandbox, demo, and drill modes.

Ruby bindings for Jolt Physics, powered by joltc, FFI, and larb

Pure Ruby LR parser generator with racc-compatible grammars, EBNF extensions, diagnostics, and SLR/LALR/LR(1) backends.

落語調の帳場言葉で書く、小さな算譜言語「噺椎」の Ruby 処理系。

A tiny Ruby library for generating finite state machine (automaton) diagrams as SVG.

Ruby FFI bindings for FreeType 2.11+, with SDF atlases and HarfBuzz text meshes.

Ruby FFI bindings for FFTW3 (Fastest Fourier Transform in the West).

Language Server Protocol (LSP) implementation for Lrama Style BNF grammar files (.y files).

Lightweight Ruby toolkit for building small music scores, parsing a LilyPond-style syntax subset, and exporting PDF, SVG, or MIDI.

Fast Prism-native AST traversal, declarative matching, and source rewriting for Ruby

WebXR Device API bindings for Ruby. Build VR/AR applications in Ruby using ruby.wasm.

Building audio-reactive visuals with a Ruby DSL.

Catch Active Record transactions napping—detect non-database idle gaps while locks may be held.

Texture-oriented image decoding, conversion, resizing, and GPU upload helpers for Ruby.

Ruby audio feature extraction library with WAV analysis and optional FFTW acceleration.

Ruby bindings for the Skia 2D graphics library.

Generate beautiful terminal screenshots from YAML.

化学式を解剖し、分子の量を秤り、反応式を釣合はすRubyGemに候

Functional, command-oriented OpenGL for Ruby.

A RuboCop extension focused on enforcing committee.

rspec-rewind is a modern retry orchestration gem for RSpec.

RSpec coverage intent metadata, strict coverage checks, and traceability suggestions.

Ruby JSON processor with a practical jq 1.7.1-compatible subset, CLI, and Ruby API.

Rdeck is a Ruby CLI tool that converts Markdown presentations to Google Slides, enabling continuous deck creation with content and design separation.

A Ruby FFI binding for PortAudio v19.

Decode PicoRuby/R2P2 Cortex-M HardFault logs with matching ELF debug symbols

Pure Ruby library and CLI for reading, composing, editing, and writing OpenUSD USDA and USDZ assets.

A Ruby audio feature extraction library that provides a full pipeline from audio loading to spectral analysis, feature extraction, rhythm analysis, effects, and lightweight visualization.

A pure Ruby library for building, reading, and writing Standard MIDI Files (SMF)

A fast, Prism-native Ruby linter

Generate Mermaid diagrams from Rails models and controllers.

Research-backed safe regression test selection and fast test feedback for Ruby.

Ruby FFI bindings for the core JACK Audio Connection Kit client APIs.

A hobby regex engine written in Ruby. Designed to be simple and efficient for educational purposes.

A differentiable 3D Gaussian splatting renderer and trainer for Ruby, with Numo::NArray and optional OpenMP acceleration.

Pure Ruby FFI bindings for GLFW 3.3/3.4.

Ruby-native lexer generator for parser authors. Write ordinary Ruby specs, run them at runtime, or generate deterministic Ruby for deployment.

Parses Terraform (.tf) files and generates infrastructure design documentation in Markdown format.

A Ruby live coding toolkit for composing musical patterns with rational time and OSC/MIDI output.

A linter and formatter for Lrama-style BNF grammar files.

Idiomatic, memory-safe Ruby bindings for Box2D v3

Ruby bindings for the Assimp 5.x asset import library