Audit Microsoft and Linux licensing with Microsoft MAP
The Microsoft Migration and Assessment Planning (MAP) tool was originally designed to help you plan your migration to HyperV. But the reports it generates are also very useful for the annual Microsoft licensing true-ups.
https://www.microsoft.com/map https://www.microsoft.com/en-us/download/details.aspx?id=7826
It can now audit Linux too (with a view to virtualising it on HyperV/Asure) http://blogs.technet.com/b/mapblog/archive/2013/01/29/determine-linux-machine-readiness-to-move-to-a-windows-azure-virtual-machine-using-the-map-toolkit.aspx
Next time you need to gather data for Microsoft licensing, check out The Microsoft Migration and Assessment Planning (MAP) tool.