Comment by RaftPeople

It's a network of high end as400's, the software is custom.

They've burned multiple 100's of millions of dollars on multiple projects trying to re-develop and move off as400's, but they just pulled the plug on their most recent project a year or two ago.

The biggest issue with adoption on new system (based on insiders I've talked to) is that the existing system is very efficient for people knowledgeable about how to use it and the newer GUI based systems just don't match it.