Dyson is a general-purpose operating system, a Debian derivative using illumos kernel, libc, and SMF init system.
It is not a successor of any existing or existed distributions based on illumos or OpenSolaris. Dyson is constructed from scratch to be like Debian as much as possible. Namely, most of Debian packages can be built on Dyson without any changes, and arch-independed packages (arch all in Debian terms) can be installed directly as is.