apt-cache

$ LANG=C apt-cache policy mono-gmcs
mono-gmcs:
  Installed: (none)
  Candidate: 3.12.1-0xamarin1
  Version table:
     3.12.1-0xamarin1 0
        500 http://download.mono-project.com/repo/debian/ wheezy/main amd64 Packages
     3.2.8+dfsg-4ubuntu1.1 0
        500 http://es.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
     3.2.8+dfsg-4ubuntu1 0
        500 http://es.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages