Steampunk
Steampunk refers to science fiction and fantasy settings that are comparable to the 19th century and the early 20th century. Steampunk often draws inspiration from the technology (both realized and unrealized -- such as the Babbage Analytical Engine), aesthetics, and science fiction of said eras. Steampunk ranges from the plausible -- in which the existing technology of the time was applied differently (such as the development of a steam powered Tank in the late 19th century) -- to fantastic with clockwork and steam powered mecha and robots and Tesla Coils.
Related terms include Clockpunk (based around pre-industrial clockwork technology), Dieselpunk (based around machinery from roughly 1914 to 1945) and Atomicpunk (based around pulp fiction and material from the 1950s and 60s).
Examples of Steampunk
- The Vinci Faction in Rise of Nations: Rise of Legends
- Steamboy
- The Girl Genius Webcomic