If you didn't know EUD, you may enjoy the seminal works Watch what I do [1] which is available online (mostly; some figures are missing) and Your Wish is My Command [2]. These books are compilations of early articles which explore very interesting approaches to building software artifacts, which look nothing like programming in a general language (though some of them resemble what Bret Victor is making popular nowadays).
BTW, spreadsheets are considered the most successful End-User Development tool; it's not coincidence that modern web languages resemble more and more its reactive programming model.
BTW, spreadsheets are considered the most successful End-User Development tool; it's not coincidence that modern web languages resemble more and more its reactive programming model.
[1] http://acypher.com/wwid/
[2] http://web.media.mit.edu/~lieber/PBE/Your-Wish/