Steampunk


Retro-style Speculative Fiction set in periods where steam power is king. Very often this will be in an Alternate Universe where the internal combustion engine never displaced the steam engine, and as a result all manner of cool steam-driven technologies have emerged, ranging from the plausible to Magitek with a Hollywood Science Hand Wave. Sometimes combined with the work of Charles Babbage on mechanical computers to produce a kind of retro Cyber Punk set entirely in the Victorian era or a close analogue, minus the exploitation.
Steam is on the rise (At least by webnerd meters), more or less replacing the near-dead Cyber Punk culture. The fact that most Victorian fiction is on the public domain helps, too. The zeppelins don't hurt either.
A related concept is "clockpunk," which is set prior to the Industrial Revolution but is otherwise essentially the same, with intricate clockworks replacing steam power as the technology of choice. On the other end, steampunk scenarios may edge into Raygun Gothic territory.