Kevin Lipe, in a follow-up post to his Pocket 8086 series here on 512:
I’d been Agenda-curious for a long time, but never tried to actually use it for real. I booted it up on my Pocket 8086, watched cards crawl into place, watched queries resolve themselves into slices of sense, and realized with annoying clarity: none of the modern “task management” apps I’ve used—not Todoist, not OmniFocus, Amazing Marvin, Remember the Milk, not Microsoft To Do—could do any of this. Not really. Agenda wasn’t “a to-do list.” It was a cognitive environment, a place where items could belong to more than one thing at once, where priorities didn’t march in a line but emergedfrom the way pieces related to one another.
This is not a user guide (Tavis Ormandy already wrote a careful, generous one here). It’s more of a lament—or maybe more of a small civic memorial—for an unexplored avenue in productivity software that modern tools only approximate in fragments. The utopian tools-for-thought vision of Agenda didn’t vanish because it was wrong; it vanished because it was weird and unprofitable.