Handling donations (especially commercial ones)

Excellent and good idea!

We're definitely using xymon for commercial purposes so buying a
license is right and proper. It's much easier to get a PO through the
system when you have an actual company and license fee sheet to point
to,  as you've done.

Suspect that paying for "consulting work" is a little tricky,
especially internationally. At least in the US paying for stuff is
easier than paying for people.