UPDATE 19 Feb 2023: As of the bookworm d-i alpha 2 release, firmware is included in the normal Debian installer images. USERS WILL NO LONGER NEED TO LOOK FOR SPECIAL VERSIONS HERE.
For older releases (11.x/Bullseye), here are are some extra images, equivalent to the normal images we produce regularly except in that they also include non-free firmware to make things easier on some systems requiring proprietary but redistributable firmware. See http://wiki.debian.org/Firmware for more details.
There are three types of image here:
The current and current-live directories contain images that match up with the latest stable Debian release.