Reddit seemed much more like a Hacker News/Slashdot interface in the early days. They were different from each other in 2005 but slowly started to coalesce into some common features that the other had first. Reddit had robust comments and threading (which I personally consider to be the defining feature), while digg version 2 had categories/tags. Reddit adopted subreddits and Digg adopted comments sometime in 2006 or so.
Reddit seemed much more like a Hacker News/Slashdot interface in the early days. They were different from each other in 2005 but slowly started to coalesce into some common features that the other had first. Reddit had robust comments and threading (which I personally consider to be the defining feature), while digg version 2 had categories/tags. Reddit adopted subreddits and Digg adopted comments sometime in 2006 or so.