HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

Regarding the game freezing after a certain amount of time. This is not a map bug; it's a hero bug. You can encounter this on almost any map where there are legions of troops and the game lasts for more than 10-15 months. Without going into detail about the reasons, I found a solution. Using a debugger, it's easy to see that the program enters an infinite loop in two places when it freezes. If you 'nop' the conditional jumps at that moment, which allow exiting the loop, then further execution proceeds without any visible issues. At least, I haven't noticed any deviations in the gameplay. Of course, you could patch the executable file beforehand, but I prefer to only patch the memory when the game freezes.