I just upgraded to ML over the weekend. All went well - until I wanted to run my one year old Parallels(version 6). Lo and behold, it does not run AT ALL under Mountain Lion! The solution from Parallels? Upgrade to Parallels version 7 at a cost of $50. Isn't that just great!! All my other apps work 100%, one or two with free updates to make them ML compatible. But oh no - Parallels saw this as a great money-grab opportunity to try and extort money from their current user base. This is unacceptable and I have vowed not to support Parallels going forward in any way. Fortunately VirtualBox works great and I will never be reliant on Parallels again. I guess it is a blessing in disguise - now I won't be bombarded by unwanted Ads every time I start up Parallels, and I would never be the victim of future attempts by Parallels to further extort money from me. Good bye and good riddance Parallels. The worst experience I ever had in buying any piece of software in my 18+ years of buying Windows and Apple software. Utterly disgusted. If there is anybody out there contemplating buying Parallels, do yourself a favour and rather try out VirtualBox, VMware or Boot Camp. You will save yourself a lot of money and effort down the road.