For me, they key pieces are: 1) frameworks. when traditional search paths don't find executables and dyn libs the way you expect, it isn't unix-alike. 1a) when

For me, they key pieces are: 1) frameworks. when traditional search paths don't find executables and dyn libs the way you expect, it isn't unix-alike. 1a) when the execution environment has changed enough that the build needs to be modified beyond a few simple config variables, it isn't Unix-alike. 2) unconventional init system. although BSD is moving to something similar to launchd, so I think that idea is evolving toward mainstream. 3) unconventional cron, see launchd/BSD. So dll dependencies are crazy-making, and Nix is attacking that. traditional init is getting creaky, launchd and systemd are attacking that. With respect to systemd, I love how it has motivated people to try to come up with something better than both traditional init and systemd.