Any version of OpenSolaris that you download IS the 64-bit version. You just download the ISO and burn it to a CD and boot it up on an amd 64-bit CPU and you now have a 64-bit UNIX operating system.
OpenSolaris is much smarter than Linux and Microsoft Windows are in that it can automatically tell whether your hardware is 32-bit or 64-bit and it will automatically reconfigure itself to run in either 32 or 64 bit mode depending on what kind of hardware it is running on (this is one of the areas in which I think the Solaris kernel engineering is superior to that of most other operating systems). If you have 64-bit hardware, but you want to force OpenSolaris to boot into 32-bit mode, you can change the parameters passed to the UNIX kernel at boot time in grub and tell it to boot into 32-bit mode that way (in spite of the fact that you have 64-bit hardware). If you have 32-bit hardware, but want to try to force it to boot into 64-bit mode, it won't work because the hardware only supports 32-bits. -- This message posted from opensolaris.org
