Friedensreich Regentag Dunkelbunt Hundertwasser[a], which was the full name he chose from himself, was an Austrian architect and painter. The three buildings in Vienna that he designed stand out: The Spittelau Incineration plant, the Vienna House of Art (Kunst Haus Wien), and the low-income housing block that bears his name: The Hundertwasser House.
Hundertwasser wrote a Mould Manifesto against Rationalism in Architecture[b], in which he argues that:
The straight line is godless and immoral. The straight line is not a creative line, it is a duplicating line, an imitating line.
The flat floor is an invention of the architects. It fits engines - not human beings.
Next to the house (across the Kegelgasse) is "Hundertwasser Village", which is a bit of a tourist trap, I suspect, but which is also a very small mall designed in the Hundertwasser-style. It has a small gallery of prints (mostly Gustav Klimt and Hundertwasser).