You'd think all the statements about interoperability after the EU
anti-trust cases would apply to Cygwin as well.
If SUA can, Cygwin should as well: "Microsoft shall ensure that
third-party software products can interoperate with Microsoft’s Relevant
Software Products using the same Interoperability Information on an equal
footing as other Microsoft Software Products. (“Interoperability
Conveniently, nothing except a press contact is given on that page.