Interesting papers, resources, etc. (math-related):

1. Quiver: a modern commutative diagram editor.
2. Grothendieck-Serre correspondences: a collection of correspondences between Alexander Grothendieck and Jean-Pierre Serre.
3. A visualization of the Hopf fibration, Niles Johnson.

Biographical writing:

1. Daniel Quillen’s memorial in Notices.
2. Life and work of Friedrich Hirzebruch.
3. Mikhail Postnikov’s life, work, and legacy. Kind of hard to find.
4. F. William Lawvere.
5. 50 Years of Masaki Kashiwara.