It is the idea of the combustion engine, and the fact that it became technical possible to build them that changed the world. It's not any particular combustion

It is the idea of the combustion engine, and the fact that it became technical possible to build them that changed the world. It's not any particular combustion engine, but the combustion engine industry as a whole. Yes, the combustion engine is very important for a car, but it became a commodity. Yes, DVCS changed the world. Git maybe more than others because of its popularity, but slowly I think they are becoming commodities. Github could function with any other DVCS and practically all major DVCS (git, mercurial, darcs, bazaar) are interoperable one with another, making the choice more personal than technological.