Cox, who was second-in-command of the kernel project until a few years go, worked for Red Hat for many years before shifting to Intel.
He said the installer for Fedora 18 was unusable and the updater was buggy. Problems with the release have already been noted in iTWire.
Cox was scathing in his criticism. "When you get it running the default desktop has been eviscerated to the point of being slightly less useful than a chocolate teapot, and instead of fixing the bugs in it they've added more," he wrote.
Cox said he was switching from running Ubuntu in a virtual machine on the machine which he ran Fedora, to running Ubuntu on the machine on its own.