Most steampunk is neither steam nor punk:
In the mid-80s, the hip new movement in science fiction was cyberpunk, which stood utopian science fiction on its head, emphasizing “high tech and low life” — cybernetics and punk — and how “the street finds its own uses for things.”
Authors who weren’t part of the hip new movement naturally resented that fact. I assume that’s what Jeter was getting at when he quipped, “I think Victorian fantasies are going to be the next big thing, as long as we can come up with a fitting collective term…like ‘steampunks,’ perhaps.”
The Difference Engine, on the other hand, actually transferred the cyberpunk ethos to the Age of Steam — where it didn’t belong, I might add — to create a true steampunk story — if not a reasonable projection of how Babbage’s analytical engine might have influenced history had it worked. Since then, the term has evolved to cover just about anything involving “retro” technology — or Victorian fashion.
The movement has also evolved in exactly the manner Robert Conquest would have expected — as the inmates at the Weekend at the Asylum explain:
“We actually have a lot to say about the modern world, recycling, upcycling, multiculturalism and inclusion,” says Rosa. “Steampunks are always really nice people, really eccentric people, and everybody is welcome, whoever you are.
“A lot of it is about social justice and freedom of expression. And eating crumpets.”
[...]
Loosely speaking, “steampunk” refers to a mash-up of 19th-century ephemera and science fiction, underpinned by 21st-century liberal values, to create a “retro-futurist vision of Victorian England”.
(Hat tip to Outside In.)
A related review essay.
And the movie review that led me to that essay.
The key passage in that essay, which was cited in the movie review: