WS-* vs. REST: Jigsaw vs. Tangram puzzle

Harry Pierson quotes Nick Gall on the value of using a small set common modular operations (i.e. the REST / WS-Transfer approach):

Modularity can be open or closed. Closed modularity is like a jigsaw puzzle. There are lots of individual pieces, but they can only be put together one way. Open modularity is like a tangram puzzle. There are only seven pieces, but they can be put together in hundreds of different combinations.