His en.wiki article is pretty lackluster: http://en.wikipedia.org/wiki/Michael_S._Hart and the other language versions don't look any better.
Roy Tennant wrote: "The best way to honor Hart’s life, I think, is to dedicate one or more works to the public domain."
http://blog.libraryjournal.com/tennantdigitallibraries/2011/09/08/to-honor-p...
He has done so and I have choosen 40+ photos from Eutin Castle e.g.
http://commons.wikimedia.org/wiki/File:Eutin_2011_04.jpg
Klaus Graf