In the cs50 manual i could only find the vmware workstation 11 link . Could you please tell me where i can find the appliance version 2014
It is a bit hidden, you actually need to enter one of the links for instructions on how to install them. The link to the current image file: http://mirror.cs50.net/appliance50/2014/releases/26/appliance50-2014-vmware.ova Or alternatively, if you prefer torrent: http://mirror.cs50.net/appliance50/2014/releases/26/appliance50-2014-vmware.ova.torrent
Remember to run update50 on a Terminal window to update to the latest version of the appliance
If you are looking to install the CS50 appliance as your native operating system instead of running it through a hypervisor (as a virtual machine) there is an iso file available.
Quoting directly from the CS50 Appliance Manual:
In case your computer is unable to support a virtual machine, or you simply prefer not to use one, and you know how to install Linux from an ISO-9660 image, we provide an ISO image that you can use to install an Ubuntu system equivalent to the CS50 Appliance on "bare metal".