[gwhl]

There is/was Subtle which I used to use a long time ago: http://subforge.org/projects/subtle/

[vidarh]

I think I've looked at Subtle, and it's interesting and worth a look, though it has design tradeoffs that doesn't fit me (and I wanted something entirely in Ruby rather than "just" scriptable in Ruby) But that's cool - my thought on this is that I'd rather have many tightly focused options than huge sprawling ones...