Depends on the DM. I've had games where everything was medieval down to the food, tech, and laws, and I've been in campagins where it really was 'modern in medieval drag' with equivilants of anything you would want in a modern game. Most of the adventures as published are probably not medieval, but I think the rules are fairly neutral. Anyway, most people I've ever played under create homebrews that have whatever flavor they want to give it.