"Mac" here means the classic Macintosh (e.g. Mac OS 7); not Mac OS X. You will need an emulator.
These are disk images with uncompressed files, so you don't need a (BinHex or StuffIt) expander.
In case you need it, here is a cheat sheet for the copy protection.
Instructions for GNU/Linux users: 2016-09-23_PoP_for_Mac_on_Linux.pdf