It includes the PortableApps Suite, Linux boot environments and a full working mini Windows 10 WinPE Boot Environment. MediCat DVD comes in four different flavors that's confusing at first, especially since you don't get good descriptions of the four options. It is still mighty useful, as it allows you to edit the Windows Registry without booting the system, reset Windows passwords, and do other things without booting into the operating system.
Hiren's Boot Cd has last been updated in 2012, and while it works in many cases, at least some of the software it ships with is outdated and may not work properly anymore on newer versions of Windows. The author of MediCat DVD designed the bootable toolkit as an unofficial successor to the popular Hiren's Boot CD boot environment.