Haskell was designed by committee, and it's exactly the opposite of the stereotype: it's a small language with orthogonal features and a clean syntax. The few "features" the language has, like list comprehensions and do notation, are defined by simple translations into the rest of the language.
And conversely, Ada was designed by one man, and if you weren't aware of that historical fact and just looked at the language spec, you'd swear it was the classic example of committee design. Fred Brooks' dictum that design should be done by a single mind, or at most two, is a guideline not a rule.
"The Ada design team was led by Jean D. Ichbiah and has included Berned Krieg-Bruechner, Brain A. Wichmann, Henry F. Ledgard, Jean-Cluade Heliard, Jean-Loup Gailly, Jean-Ryanmond Abrial, John G. P. Barnes, Mike Woodger, Olivier Roubine, Paul N. Hilfinger, and Robert Firth."
Right, but wasn't it structured as 'Ichbiah assisted by the others' rather than 'Ichbiah leading a committee by consensus'? In particular, iirc, there were some points at which the others almost unanimously disagreed with Ichbiah on some design decision and he overruled them and went ahead anyway.
http://www.haskell.org/onlinereport/