A slightly sketchy, but as of yet woefully incomplete, short note about Koszul duality (more accurately: Bar-Cobar duality) between modules and comodules.
A short meditation on En-crystals (also known as En-D-modules). To be explored further in forthcoming joint work with David Ben-Zvi and Pavel Safronov.
This is infinity cat, the horn filler; I often encounter her on my mathematical journeys.