Agreed, we essentially need to take stock of all proprietary software running and suggest alternatives for testing that can be presented.
We must just agree on the aims: do we do server side first, desktop OS, or end user apps with a view to readying the OS for change. Windows 7 support coming to and end means Microsoft has gov in a never ending spiral of payment and change.
But yes this list will provide a checklist of what must be tackled. I’m just thinking also about how broad we tackle this: A product across all Depts, or do a specific Dept first and migrate them for all products.
Obsidian Systems has done at least one survey across Gov and may also have some good inputs regarding change.