I love this stuff!
Wether the maker/gamer labels it as Inquismunda, =I=Munda, Inq28, ItEN or whatever (and whichever rules they use), to me it boils down to just one, simple, beautiful, notion:
Play the setting and the art, not the game. Follow your imagination instead of the rules.
Inspiring, and a wonderful attitude to approach the/any game.
And I have to agree with PatrickWR: nothing like those wonderful, anarchic old books and art.