In reply to Exchange characters by random (opentype):
thank you, Pieter!
for other’s looking for the same, I also found these:
http://www.underware.nl/case-studies/
http://letterror.com/foundry/beowolf/
http://graphicdesign.stackexchange.com/questions/11342/how-does-random-c...
http://glyphsapp.com/forums/index.php?action=vthread&forum=1&topic=232