If you had trouble getting JP to mount on your Mac- I have a foolproof workaround!
PROBLEM: The JP .dmg file downloads perfectly fine on your computer, but when you click it, nothing happens.
SOLUTION: This is a mounting problem.
1. Control-click (or right click with two-button mouse) the .dmg file.
2. Go to "Open With" and choose Disk Utility
3. This will open the Disk Utility. MAKE SURE "JurassicPark100_Setup.dmg" is the file selected.
REPEATING. MAKE SURE "JurassicPark100_Setup.dmg" IS THE FILE SELECTED.
4. Hit the Convert button. It's on the top of the toolbar in the Disk Utility window.
5. Change the image format to "read only", choose a destination (I picked the Desktop), and hit "Save".
6. Click the new .dmg file you have created. JP will now mount, and you can drag the JP folder onto your computer as normal.
This fixed it for me, and JP is running great. Good luck!