After looking at:
Where can I download Northwind database for Postgresql?
it looks like the best place for Northwind data, outside of the Microsoft itself, is:
https://code.google.com/archive/p/northwindextended/downloads
to what extent does this raw data match the Microsoft data? Is there any advantage in downloading directly from Microsoft?
I'll be using either MySQL or SQLite, mostly on Linux. The Microsoft site at least emphasized their SQL Server, of course.
See https://github.com/jpwhite3/northwind-SQLite3
"All the TABLES and VIEWS from the MSSQL-2000 version have been converted to Sqlite3 and included here. Also included are two versions prepopulated with data - a small version and a large version"