The Ruby Compendium has been updated, and it now lists the most up-to-date versions of various Ruby implementatios, even more web sites, books, podcasts, and Rubyists. In addition to the PDF version, the book can now be read online here on H3RALD.com.
Overall, this is a relatively minor update; however, I felt it was a good time to release it to keep the book up-to-date.
The Ruby Compendium is available free of charge, under the terms of the Creative Commons Attribution-ShareAlike 3.0 Unported License, and you can help improving it! It was written using my very own Glyph Framework, and the entire source code is available on GitHub, for anyone to fork.