Why can't I install LibreOffice on my Mac OS 10.7.5

According to the system requirements, version should work on my Mac OS X 10.7.5 MacBook. But when I want to open it, it says that the program requires Mac OS X 10.8 or later. I downloaded the 64 bit version here: Index of /libreoffice/old/
Any ideas?

It requires Gatekeeper to be set to “Identified Developers” or lower during installation. See my answer to Q64923 for fuller information.