I purchased PD10 shortly after release in 2014. I was under the impression that Parallels supported their product for 2 years from release. The email I received from Parallels today whilst emphasising I will still be able to use PD10 with El Capitan the pledge comes with a number of caveats. Given this email and the fact El Capitan offers little I am interested in over Yosemite, I won't be bothering to upgrade OS X this time around. email from Parallels - OS X El Capitan - Coming September 30 Parallels Desktop 10 for Mac will run on OS X El Capitan (10.11) as long as you are on the latest update; however it is not optimised or enhanced for El Capitan. You will NOT be able to drag and drop files from Windows to Mac or use Windows Applications in full screen*. To enjoy an El Capitan optimised version of Parallels Desktop, please upgrade to Parallels 11 Desktop for Mac. Not amused by Parallels CS.