Scala Plugin missing in IntelliJ IDEA 11.1.1

I am trying to install the Scala plugin for IntelliJ IDEA, but it does not appear in the list of plugins.

I am using version 11.1.1

Btw, it really appeared a few months ago on my other computer, it uses version 10.5.2. Here is a snapshot ..

Has something changed now to install the plugin? I tried Google but did not succeed.

Any solution / workaround?