https://www.bit-tech.net/news/tech/software/apple-releases-macos-10-5-5-update/1/
Apple releases Mac OS 10.5.5 update | bit-tech.net
Apple has released the latest update - 10.5.5 - to its 'Leopard' release of Mac OS X, and it brings with it some important security fixes for the OS.
mac os 10 5bit techapplereleasesupdate