I learned that computer scientist Peter Landin passed away recently. Landin's research helped refine the direction of my college studies, and was always a great pleasure to read. His derivation and explanation of the SECD machine served as the basis for a more mature and clear understanding of many aspects of programming languages and their evaluation. And, of course, there was his classic paper "The Next 700 Programming Languages", which provides an interesting perspective on programming languages, where they should were, where they are going, and what is significant about their design. Great stuff!
Addendum: Here's my attempt to embed a link to this paper here.