It's much closer to a desktop linux distro - it still uses glibc afaik, and other more "standard" linux bits (eg pulse audio and dbus and x11 and rpm and gstreamer etc - see here for more info: https://wiki.merproject.org/wiki/Architecture - Sailfish is based on Mer, so the architecture should be fairly similar) Android has way more bits that have been made explicitly for it - many of which were made to BSD license-able (or so I've read) :-)