Q I am ashamed to admit this, but we still need to be able to run software which is PowerPC-only. Our sole remaining Power Mac has been working OK, but we are worried how much longer it will last. What is the best way of keeping this legacy software alive?
A There are only two effective strategies to maintain access to PowerPC-only apps which cannot run under Lion.
The first is to keep an old Mac, running Snow Leopard which retains Rosetta, the component enabling PowerPC apps to run on Intel systems. That means a model which was launched before July 2011, when Lion was released. Perhaps your best bet would be to hunt down a couple of Mac Pros (Mid 2010, MacPro5,1) which should be happy to run OS X 10.6.8, are well-engineered, and should be maintainable for a few years to come. Try to get at least one spare in case you need to cannibalise it to keep the other going.
The other is to run Snow Leopard under Parallels or VMware virtualisation. However because of licence limitations, they will not normally accept the client version of Snow Leopard, and you will have to virtualise either Leopard or Snow Leopard Server instead. Try to check that this option is compatible with your legacy software before committing to it. You may find suggestions as to how you can virtualise client versions of OS X on various sites, but they are in breach of Apple’s licence.
Updated from the original, which was first published in MacUser volume 28 issue 14, 2012.