Ars is reporting that the Gold Master of Mavericks has been released to developers. So hopefully shortly it will be available to the rest of us. It will, of course, take some time after that for apps to be updated to be compatible with Mavericks. Adobe After Effects is one of several apps that I discovered the hard way this past summer do not currently launch at all running Mavericks. Adobe has promised an update upon the public release, but they already have their hands full with other issues these days.