Contents under contrib/non-profit-audit-reports/ are licensed GPLv3-or-later.

The GPLv3-or-later licensing of the contents of this directory does not,
to our knowledge and belief, impact the licensing of any other part of
Ledger.  Parts of the files herein are likely derivative works of the rest
of Ledger, but these works are under this subdirectory are not, to our
knowledge, used, imported, included, copied, etc. into other parts of the
codebase.

In short, this is a small application written to use Ledger like a
library, particularly via its Python API interface.  It derives from
Ledger, but Ledger does not, to our knowledge, derive from it.

We are not lawyers and this is not legal advice.
