This is pretty cool. But what is the target audience? Is it for people who already know how to program? I think some novices would have a really hard time just with downloading, running the right file, understanding the output enough to open the right source file, and then know how to edit that file just based on what was in it.

But a PHP programmer or something... they should be able to do it.

I've always felt neglected trying to find tutorials that will actually help me as a programmer learn a new language, as opposed to tutorials that spend a lot of time teaching how to program.

What a great tool! This tutorial definitely teaches you the Ruby language, rather than programming in general.