I just heard that David Weininger had died last Wednesday, for me his invention of SMILES was one of those ideas that you instantly knew was going to change the way we did science. So much of what we do in storing, searching and analysing chemical information is based on his pioneering work. I only met him once at a Daylight UGM but it was clear from our first conversation that he was a scientist with a special insight.
SMILES as a simple yet comprehensive chemical language in which molecules and reactions can be specified using ASCII characters representing atom and bond symbols
Anthony Nicholls of OpenEye has written a lovely tribute that is well worth reading