I work for medium sized university with the IT dept basically split into two sides, Business and Academic. The business side tends to skew to the > 40 side of the age spectrum and deals almost exclusively with IBM, Oracle, and Microsoft. If its not prepackaged solution more than likely its not being considered. There are a few Java developers, but lots of legacy mainframe code still exists. Most of the identity management is currently on IBM mainframes but being moved slowly to a packaged identity management system. There are few java programs intermixed with lots of Cobal programmers.
I work for the academic side, which skews much younger. Most of our systems are Linux with a sprinkling of Solaris, but with the rest of the stack is postgres, mysql and php. Most of our software is written in house and instead of writing to a peoplesoft/oracle stack its coded for ldap/mysql using perl and php.
We essentially accomplish very similar tasks. The only difference is that that Business side costs a ton of money and requires much beefier machines to handle the Java stack vs the Academic side has smaller machines (though some horizontally scaled) on free and open stack.
Of note, the Business side budget is far larger than the Academic side.