FtP old vst effects are free?

the vst files of ftp://ftp.steinberg.net/Archives/ are free to use with other daw than cubase?
Is cubase 3.1 free?

I think you’ll find that all the individual VSTs are only updates - so you need the original.

Cubase 3 will only work if you have a licence for Cubase 3 or higher on your dongle. Its supplied complete as its the last version that will import ‘Cubase VST’ .all project files, and will convert them to the .cpr project file format used by all the more recent Cubase versions.