How to install Leopard Os X 10.5 on single-layer disc DVD or how to mount DMG is the question now, when Leopard is on torrents and you don’t have original DVD, or dual-layer DVD burner.
There are two known methods, i found surfing the net, that can help to install Leopard. But i didn’t test one or another:
GUIDE: Installing OS X Leopard on a single-layer disc
Installing Leopard From DMG
Use at Your Own Risk!
I bought the original Leopard Os X 10.5 on dual-layer DVD for 12€.