Ultima IV part 2 is a freely downloadable parody game, made with the Adventure Creation Kit
From the game's website, http://www.80sgaming.org/ultima-parody/
Ultima IV Part 2 is a parody of the Ultima series. It takes place in the gap of time between Ultima IV and Ultima V. It answers some of the unresolved questions from the series:
How were the dungeons sealed?
Why did Lake Generosity dry up?
How was Blackthorn able to take over?
Why did the Shadowlords really come to Britannia?
How was the Codex raised out of the Abyss?
But why stop there? The game also pokes fun at the entire Ultima series:
What really happened to Mondain, Minax, and Exodus?
Why did the Stranger/Avatar stop going into space?
Where did the Guardian really come from?
Why did Lord British's castle have an entrance to Hythloth?
Why is Humility really one of the eight virtues?
Just how crazy of a set of virtues will Britannians follow?
Who cares? (Okay, it doesn't answer that.)
This game was developed with the Adventure Creation Kit software, a free game engine that is now nearly as old as the games as I'm lampooning (it was first released in '91.) The new version of ACK is updated and optimized to run under DosBox with better support for sound, pictures, etc.