A barcode and QR code library that works with regular Ruby (not just JRuby). This gem comes bundled with ZXing C++ (zxing-cpp) and interfaces with it using FFI. As such this gem works with most major Ruby distributions.

Zen by Aikido is an embedded Web Application Firewall that autonomously protects Ruby apps against common and critical attacks.

Deterministic Bitcoin Address Generator.

Celluloid bindings to the ffi-rzmq library

It aims to be a feature complete Ethereum implementation and expects to achieve both research-friendly and high-performance.

A fast library for Constructive Solid Geometry

Simple wrapper around libcups to give CUPS printing capabilities to Ruby apps.

Given packages, versions, and a dependency graph, find a valid assignment of package versions

FFI bindings for Aspell

Ruby FFI bindings for libclang C interface.

A generator for Ruby FFI bindings, directly from header files via LLVM's Clang compiler

An FFI wrapper around ncursesw 5.x for MRI Ruby 1.8.x, 1.9.x and JRuby.

This gem provides only the FFI wrapper for the ZeroMQ (0mq) networking library. Project can be used by any other zeromq gems that want to provide their own high-level Ruby API.

A generator for Ruby FFI bindings, directly from header files via LLVM's Clang compiler

Automatically reloads your Rack based app on file change using Guard.

Hallon allows you to write Ruby applications utilizing the official Spotify C API.

Nested OpenStruct optimized for short-lived objects.

Ruby 1.8's IO.select() smashes the stack when given >1024 fds, and Ruby doesn't implement IO.poll().

krypt provides a unified framework for Ruby cryptography by offering a platform- and library-independent provider mechanism.

LevelDB for Ruby