Oldest Supported Software?

Dave Santek writes "In development since the early 1970s, the McIDAS [Man computer Interactive Data Access System] software celebrated its 30th anniversary in October 2003. McIDAS is used to integrate and visualize weather information. The software was originally run on a Datacraft /5 and has gone through 4 major hardware configuration changes over the last 30 years. It is a supported software package that remains in use at more than 100 locations worldwide. A history of the first 25 years (pdf) is available. A freeware version of the software is also available."