Just install VirtualBox and load it all into a VM; that's what I do. I've given up on VirtualBox for 10.5, but 10.4 and 10.6 through 10.11 run perfectly well in it. Running 10.4.11 PPC with Mac OS 9.2.2 in qemu-ppc and VirtualBox with 10.6.8 will let you run pretty much any legacy Mac software not slaved to external hardware or a less than 640x480 screen resolution. For the former, I have a few PPC minis kicking around; for the latter, Mini vMac.
That said, the original thread was for one of theh 10.11 point updates; 10.12 is running fine for me, but I've lost support for a few pieces of software, and the only compelling new thing I've seen is Siri, which I haven't even used for anything useful yet since I upgraded months ago.
Let me know if you need help installing Snow Leopard; it's a bit tricky on later model Macs and recent versions of VirtualBox.