The KiwiRail Freight Booking System. The first version of this system was originally built by Clearfield in 2001, and it's been steadily improved upon ever since. These days, it not only handles container bookings, but also manages a multitude of other tasks. For example, it's responsible for managing container terminal operations, loading and unloading trains, generating forklift work orders and tracking refrigerated goods.
It's an EJB application, running in WebSphere. The front end is written in Amber, a thin Java client.