The Lion SLA does state that whilst you can use one copy of Lion to install onto all of your Macs, it is specific in that it needs to be a “computer running Mac OS X Snow Leopard or Mac OS X Snow ...

If you're willing, you can install newer versions of macOS than your Mac supports with ... physical versions of OS X on its website, but there might be old copies of Lion, Mountain Lion, and ...

For those who have been keeping their Macs up to date with Apple's pantheon of exotic felines, upgrading to Mountain Lion should be fairly straightforward, require less than an hour (not including ...