[Haskell-cafe] Is there a tutorial interpreter to teach haskell?

[Stephen Tetley]

Andy Gill developed HERA which sounds somewhat similar to what you are
asking, but I don't know that it would be particularly beginner
friendly and I think it was static - i.e. the reduction rules were
applied to program source code rather than within an interactive
evaluation of a running program. I thought I'd seen more information
about it on the web, but all I can seem to find at the moment is this
page:

http://www.haskell.org/haskellwiki/Haskell_Equational_Reasoning_Assistant

Maybe a debugger like HOOD or HAT would be usefully illustrative for
runtime evaluation? I think HOOD is back working with recent GHC's.