I am pretty sure it's more for historical reasons than a solution from MS for long filenames on win32. It's due to the application writing to the file-system, n

I am pretty sure it's more for historical reasons than a solution from MS for long filenames on win32. It's due to the application writing to the file-system, not the OS. Earlier DOS FS (and others) were sometimes limited to 8 characters + 3 for extension and Windows just used to shorten filenames when writing to those FS. But to these days it still causes some problems for legacy software and you might see some PROGRA~1 hanging around but it's not from the OS, it's from the application (or its old out-date API for FS access) doing the shortening to fit the long filename it was given into an 8 characters word it thinks the FS can handle. Windows's file explorer or file picker doesn't shorten path or filenames when downloading long filename from the web for instance (via Firefox or IE).