OpenSolaris

Install into VirtualBox

Start the VirtualBox, create new virtual machine (name it MilaX), select Solaris OS type, create new disk image for this virtual machine.

In the main VirtualBox window, click Settings and then click CD/DVD-ROM.

In the CD/DVD-ROM settings, select Mount  CD/DVD Drive, and ISO Image file (milax031.iso).

Click Start button and MilaX boots from ISO image.

After booting create a Solaris partition and slice for the root filesystem - more here. 

Install Milax on the virtual disk using zfsinstall:

Reboot and boot from virtual hard disk:

MilaX VirtualBox images available on VirtualBox Images site.