As far as I'm aware, Interix (SUA) uses no undocumented interfaces. The kernel subsystem interfaces are actually quite nicely documented; I was working on a Da

As far as I'm aware, Interix (SUA) uses no undocumented interfaces. The kernel subsystem interfaces are actually quite nicely documented; I was working on a Darwin subsystem for a while, using SUA as a nice reference ("along with Windows Internals"), and it's really quite nice.