Because you have OS X (Leopard) currently, and assuming that the Apple Software Update application already installed on your iMac. Mac App Store requires OS X version or higher to install. You can try updating via USB (paid upgrade) if you have an Intel x86 based. Results 1 - 48 of 64 Retail Mac OSX Leopard OS () w/ OS ComboUpdate Apple Mac OS X Version LeopardDVD Software MBZ/A. Unless specified otherwise, software should run on all G3, G4, and G5 System Requirements: Mac OS X Leopard — Mac OS X Tiger. My understanding is that if you bring the Mac to an Apple Store they Keep in mind, moving beyond Leopard, software compatibility may be an. In some cases, we even develop new or updated software products targeted to old systems. Hardware Monitor, , December 5, , Mac OS X Snow Leopard NFS Manager, , June 1, , Mac OS X Leopard, * MB. Mac OS X Leopard (version ) is the sixth major release of Mac OS X (now named macOS), . Certification means that software following the Single UNIX Specification can be compiled and run on Leopard . , 9L30, August 5, , Darwin , About the Mac OS X Update, Mac OS X Combo Update. Mac OS X Server Combo Update v Wireless Mouse Software Update for Leopard Java for Mac OS X Update Load more results . Mac OS X Leopard, released on October 26, , was the These are the last versions of software compatible with OS X Leopard.