NoCat

From the documentation (what there is of it) for the authentication part of NoCatAuth (http://nocat.net/), and the code, it looks as if it should be possible to create a version that used Raven for authentication quite easily, either exclusively or in a "click here for Raven, otherwise enter your local id/pwd here" mode. However doing so would probably require a new version of the main 'login' cgi, but that's fairly self-contained and only short (a couple of pages of Perl).

Someone who has adapted NoCat to work with the University of Washington's PubCookie authentication system (which is similar to Raven) wrote:

   Here's the short version what I did:

   1) Modify the login script to skip authentication and jump directly to notifying the 
   gateway that the user is authorized

   2) Protect the login script with Pubcookie (or raven)

   The gateway should be configured to redirect to the login script. The user is then    
   prompted for university credentials, and finally the login script connects back to the   
   gateway.

Dave Eyers <David.Eyers@cl.cam.ac.uk> has successfully deployed a couple of NoCat systems using Raven for authentication. A writeup of how he did at least one of these is available at http://www.cl.cam.ac.uk/~dme26/UCamNoCat.html