For those who don't know, steampunk is science-fiction set in the Victorian era with steam-driven technology that is a little too advanced. Think about the tank and submarine in League of Extraordinary Gentlemen.
So, this month I have two stories labeled "steampunk" coming out.
The thing is, only one of the stories is steampunk. The other is gaslight romance.
Let me explain:
Let's say you write a story about a brass robot worker who runs on steam.
If you write it with the "ooh, shiny, look what we did! We're so clever, let's save the world!" tone, it's an Edisonade.
If you write it that the hero has done this to get rich, relieve his drudgery and marry his lady-love, it's gaslight romance.
If you write about the robot putting workers out of jobs, because it doesn't need food or wages or sleep, and the workers revolt, you have steampunk.
Steampunk has been summed up as "an argument with the SF of earlier eras." The steampunk shiny always comes with a dark flip-side. An Edisonade is a story that focuses on the inventor, usually a man, who comes up with something really brilliant. There is no dark side to his shiny.
Sure, we can build a deep-sea vessel, maybe even an undersea city. That's your Edisonade: the bright-boys building, overcoming obstacles and achieving a brainiac uptopia. Steampunk explores questions like "who gets to live in the city?" If it's built by bright-boy inventors who form an all-male inventing club and don't let women or "lesser minds" in, who is going to do all the things they think are beneath them? And when they let the lesser folk in, what happens when the lessers want to invent as well?
Gaslight romance uses the high-tech trappings of steampunk to tell stories that are not challenging to the status quo, but not "oooh, shiny" of the Edisonades. In Gaslight Romance, characters take their everyday tech for granted. They like it because it works. They seldom tinker with is. The story they are involved in does not center on the tech, nor does it quarrel with the tech or (too much) with society.
Hence "Skyway Robbery," with Robin and his crew specifically targeting "Edisonian" ships, taking from the bright-boy-inventors-turned-sweatshop-owners and funding workers is explicitly steampunk. But "Cherry Tart," with Chastity and Ulysses falling in love being the main focus, and even the trip to Io in a brass and wood ship being secondary, is pure gaslight romance.
A side note
There are many other -punks:
Bronzepunk: 300 is a good example of this. Swords and Sandals with extra. Archimedes was the father of Bronzepunk tech and should be used as often as possible 8)
Clockpunk: Renaissance period
Dieselpunk: Post-Victorian, pre-Atomic age.
Atompunk: Hard to separate from cautionary tales and 1950s Big Bug movies. Technically, The Hills Have Eyes remake would be Atom and Splatterpunk.
Cyberpunk: Science fiction, usually dealing with humans and machines interfacing. This was the first of the genres, and Gibson's Neuromancer is still considered the seminal work.
Mythpunk: use of post-modern elements in classic elf and fairy stories. Catherynne M. Valente specializes in this.
Splatterpunk: really excessively gory horror.