This Ruby extension implements a DataMatrix encoder for Ruby. It is
typically used to create semacodes, which are barcodes, that contain
URLs. This encoder does not create image files or visual
representations of the semacode. This is because it can be used for
more than creating images, such as rendering semacodes to HTML, SVG,
PDF or even stored in a database or file for later use.

Once you have a visual representation of the semacode, you can use a
reader, such as those from http://semacode.org on your camera phone,
to capture the URL embedded in the semacode and proceed directly to
that web site.

You need a mobile camera phone supported by or listed in

  http://semacode.org/about/hardware/

The software is available via ruby gems (gem install semacode) and you
can find source at

  http://rubyforge.org/projects/semacode/

To find out more, please view the README at

  http://rubyforge.org/docman/view.php/3201/705/readme.html

-- G.