The only software that the Calculator can run on is Microsoft Excel for PCs 2007 and 2010, and Microsoft Excel for Macs 2011.
The reason is that the model includes “structured references” and these have not been implemented in earlier versions or in open source Excel alternatives.
Possible work arounds:
- Download trial copies of the latest version of Microsoft Excel
- Programatically drive the ruby version of the calculator, distributed as part of the source code to the web interface: http://github.com/decc/twenty-fifty