The most popular mainstream adopter of rotary-style engines is Mazda, as is the case with an RX8 engine. Some of their other higher-end sports cars, like the RX-7, were also powered by rotary engines. This began a long time ago, with Mazda's Cosmo being the first from the brand to offer a rotary, back in the 1960s. In more modern times, no other major automaker experimented with rotary designs as much as Mazda, especially not in production form. Although, Mazda wasn't the first to use a rotary engine. This honor goes to NSU, an old West German automaker, and their Wankel Spider. Besides Mazda, other brands worked with NSU to develop rotary engines, as well. For example, Citroen would go on to build the GS Birotor, though only 837 of them were built.