Recumbent (meaning seated) bikes have been around for quite a while, but have never garnered a significant share of the market. The last I heard, they had just slightly more sales than Tandems, and you know how rare those are. Yet lately you are starting to see them in increasing numbers.
Recumbents or "Bents" as they are often called in the US and Canada (but seldom in Britain due to another connotation of the word) started out as a tinker’s project. Often they were, and some still are, assembled in garages out of pieces and parts of cannibalized bikes by guys with a welding torch in their hand and a gleam in their eye. Today, there are a couple of dozen manufactures of quality production recumbents in the US, Europe, Australia, and the Orient.