rqrcode is a library for encoding QR Codes. The simple interface allows you to create QR Code data structures and then render them in the way you choose.

Render QR codes with Rails 3

Glues rQRCode together with chunky_png

Ruby bindings for ZBar, a barcode recognition library. Uses FFI to interact with the underlying C library, but has no other dependencies.

Need to decode 1D/2D bars and don't mind using JRuby to help with the task? ZXing is the wrapper for you!

Ruby gem QR code scanner based on ZXing

A ruby library to create qrcode. Output: PS, JPEG, PNG, EPS, TIFF.

QRTools is a library for decoding QR Codes. It relies on libdecodeqr for decoding.

This Gem is a wrapper around an useful open-source library for creating QR Codes, a two-dimensional bar code format popular in Japan created by the Denso-Wave Corporation in 1994.

Ruby Gem to generate PNG files with QR codes in them