Poignant Guide link broken

[Apocryphon]

At the very end of the tutorial, the info mentions this:

Once you have Ruby installed, you can use Interactive Ruby by running irb on your system's prompt. For more on Irb, there's The Tiger's Vest to help you.

Unfortunately, the Tiger's Vest site is no longer available, and the link leads to a domain parking page (http://poignantguide.net/ruby/expansion-pak-1.html).