This is explanation what SchilliX currently is (yes its complicated) from its author:
Originally Posted by Jörg Schilling
"SchilliX is not based on OpenIndiana as OpenIndiana has incompatible IPS packaging. SchilliX uses the native Solaris packaging system. SchilliX is rather based on OpenSolaris, but note that OpenSolaris is not a distribution. The name of the distro you call 'OpenSolaris' is Indiana. And OpenIndiana is based on Indiana and not on Solaris as Solaris is the non-free precursor of OpenSolaris. To be more precise, OpenSolaris is the 'open' Solaris base. The development code name for Solaris 10.1 (renamed to Solaris 11 at the end of 2005) is 'Nevada' and the source base (that is similar to what FreeBSD covers with their code base) is called 'ON' (Operating and Networking). Before Oracle launched their recent closed-source fork from OpenSolaris, the OpenSolaris base was called 'ONNV' by Sun. ONNV in an abbreviation for 'Operating and Networking Nevada'. SchilliX-ON is a continuation project for that code base and SchilliX is based on SchilliX-ON."