Gem force from https://rubygems.org/gems/pdf-writer, as ywesee does not want to rewrite its code to move to ruby 2.x
PDF::Writer for Ruby
This library provides the ability to create PDF documents using only native Ruby libraries. There are several demo programs available in the demo/ directory. The canonical documentation for PDF::Writer is "manual.pdf", which can be generated using bin/techbook (just "techbook" for RubyGem users) and the manual file "manual.pwd".
Homepage:: http://rubyforge.org/projects/ruby-pdf/ Copyright:: 2003—2005, Austin Ziegler
This software is based on Adobe's PDF Reference, Fifth Edition, version 1.6. This and earlier editions are available from Adobe's PDF developer website[http://partners.adobe.com/public/developer/pdf/index_reference.html].
Ruby 2.0 Compatibility
This gem version has been updated to work with Ruby 2.0. This is a maintenance effort only to support moving existing projects from Ruby 1.8 to 2.0. New project development should use Prawn over PDF-Writer as it is actively maintained and is also the successor/rewrite of this library.
Please read the file LICENCE for licensing restrictions on this library, as well as important patent considerations.
PDF::Writer requires Ruby 1.8.2 or better, Color 1.4.0 or better, and Transaction::Simple 1.3.0 or better.