There was a conference yesterday in his honour in Paris: https://serre100.sciencesconf.org/

Serre wasn't there, but did a talk over Zoom from Switzerland where he now lives. I wasn't there either, but followed (and enjoyed) his talk over the YouTube stream. This was both a reminiscence of the mathematics of the 50s, and reflections on the role of counterexamples in mathematics.

Fun facts: Serre is still the youngest mathematician to be awarded the Fields medal, at 27. And Serre still publishes mathematics papers, the last one in 2025 (he was 99). A volume V of his Collected Papers (1998-2025) was published this summer by Springer. What a career!