rqrcode_core is a library for encoding QR Codes in pure Ruby. It has a
simple interface with all the standard qrcode options. It was originally
adapted in 2008 from a Javascript library by Kazuhiko Arase.

Features:
* rqrcode_core is a Ruby only library. It requires no 3rd party
  libraries. Just Ruby!
* It is an encoding library. You can't decode QR Codes with it.
* The interface is simple and assumes you just want to encode a string
  into a QR Code, but also allows for encoding multiple segments.
* QR Code is trademarked by Denso Wave inc.

rqrcode_core is the basis of the popular rqrcode gem. This gem allows
you to generate different renderings of your QR Code, including png, svg
and ansi.