Syntac Highlighter for Ruby

docrb-parser is responsible for parsing Ruby sources into a structured format for usage by docrb and docrb-html.

An Inngest-style durable workflow runtime built on ActiveJob::Continuable, Active Record, and Rails.event.

Evilution is a mutation testing tool for Ruby. It validates test suite quality by making small code changes and checking if tests catch them. AI-agent-first design with JSON output, diff-based targeting, and coverage-based filtering.

Use Fastererer to check various places in your code that could be faster. A fork of fasterer (https://github.com/DamirSvrtan/fasterer) with Ruby 4.0 support and native Prism parsing.

A HAML to ERB converter for migrating Rails views. Handles tags, attributes, Ruby code, blocks, filters, and interpolation.

Hen'i-tai (変異体) is a mutation testing framework for Ruby 4+. It produces Stryker-compatible mutation-testing-report-schema JSON, integrates with the Stryker Dashboard, and ships with a standalone HTML report powered by mutation-testing-elements. A free, open-source alternative to the mutant gem — with built-in cost-reduction strategies, per-test coverage analysis, and CI/CD integration out of the box.

A tool to generate LSIF and SCIP index files for Ruby codebases

Combines static AST analysis with runtime profiling to prioritize performance optimizations by actual impact

Immosquare-cleaner streamlines Rails applications by running tools like RuboCop, ERBLint, Stylelint and more. It ensures code quality, readability, and consistency across the application.

Import specific constants from a file, into the global namespace or into another constant.

Snapshot testing for Ruby with inline snapshots, difftastic diffs, and interactive review. Supports Minitest and RSpec."

Kaisoku selects impacted Ruby tests with safe fallbacks, dependency maps, parallel execution, and evaluation tooling.

Evaluate the similarities and differences in your objects. Art does not reflect what is seen, rather it makes the hidden visible.

Konpeito is a gradually typed ahead-of-time compiler for Ruby with Hindley-Milner type inference and dual LLVM/JVM backends. Compile Ruby to CRuby C extensions (.so) or standalone JARs with seamless Java interop. Includes Castella UI, a reactive GUI framework powered by Skia, based on a port of Castella for Python (github.com/i2y/castella).

Generate Mermaid class and ER diagrams from Rails models, controllers, and database metadata.

JSON Driven, Stateless Rules Engine for JIT and efficient evaluation of complex rules and computation graphs.

lilac-cli compiles .lil single-file components (template + Ruby script) into static HTML for the Lilac component runtime on mruby-wasm.

linecounter scans a git repository and reports per-file quality signals: non-empty lines of code, git churn, control-flow branching, and class-structure counts with average statement lines per item. Output as text or JSON.

PRISM is amazing but we need to use it responsibly and only load the AST once, do that with Lowkey!