Today I helped out a friend, he tried to upgrade a server from Ubuntu 12.04 to 14.04 and something went wrong. I'm not exactly sure what went wrong but after tinkering a little bit I got it working. Doing that passenger (a apache mod) got updated and needed a config.ru file in the root to start the rails 2.3 app. But then it just worked.
It was a rails app I wrote in 2013 which is used unchanged daily by 35 users to log work time in a small company.
They really got their money's worth.