Generated from:

=stealth,swap,
  node/.style={draw,minimum width=24mm,text centered,minimum height=14mm}]

  \filldraw[fill=green!10,dashed,rounded corners=5mm]
    (-1,-8) -- (4,-8) -- (4,-11) -- (-1,-11) -- cycle;

  \filldraw[fill=blue!10,dashed,rounded corners=5mm]
    (6,-5) -- (13,-5) -- (13,-11) -- (6,-11) -- cycle;

  \node at (1,-10.5) {Foo};
  \node at (10.5,-10.5) {Bar};

  \node [node] (impl) at (1.5,-9) {Baz};

  \node [node] (lang) at (8,-6) {X};

  \node [node] (algo) at (11,-6) {Y};
  \node [node] (proto) at (9.5,-9) {Z};

  \draw[->] (lang) to node {} (proto);
  \draw[->] (algo) to node {} (proto);

  \draw[->,bend left] (impl) to node [swap,text centered]{Woo} (lang);
  \draw[->,bend right] (impl) to node [text centered]{Woo} (algo.south west);

\end{tikzpicture}

\end{document}
]]>

then running tex4ht via mk4ht htlatex demo.tex