Sad to hear that Daniel Bobrow has passed away. I never met Bobrow, but he's one of those people whom I've read about and have just been blown away by how much they've done. Some incredible things he did:

Was one of the original authors of LOGO
Worked on many cool lisps, including Interlisp and BBN Lisp
Wrote STUDENT, one of the big breakthrough AI programs
Worked on the TENEX operating system
Worked on the Common Lisp Object Standard, CLOS

I loved watching the video of him talking about CLOS, both for the content, and for the entertaining clarity and crispness of his presentation style.

Thanks for all you did, Bobrow. Best wishes to your family.