Another subgenre is "biopunk" (cyberpunk themes dominated by biotechnology) from the early 1990s, a derivative style building on biotechnology rather than informational technology. In these stories, people are changed in some way not by mechanical means, but by genetic manipulation. Paul Di Filippo is seen as the most prominent biopunk writer, including his half-serious ribofunk. Bruce Sterling's Shaper/Mechanist cycle is also seen as a major influence. In addition, some people consider works such as Neal Stephenson's "The Diamond Age" to be postcyberpunk.