The three seem to be the same, at least at large magnification:

Where are the differences?

In the size of the character set. 

36 minutes ago, Ralf Herrmann said:

In the size of the character set. 

What do you mean by the “size”? The cardinality of the set, i.e., the number of characters?

Yes. 

https://www.linotype.com/en/1697-21120/opentypezeichenstzeopentypestd.html

https://www.linotype.com/en/1697-21121/opentypezeichenstzeopentypepro.html

https://www.linotype.com/en/1697-29912/w1gschriftenwgl4.html

@Ralf Herrmann Thx! I am surprised that it was possible to typeset Cyrillic letters using Std and Pro, whereas the spec you cited doesn't contain Cyrillic letters. Any idea why? I used libreoffice for typing the above.

Try to deactivate the W1G in FontBook and see what happens. 

On 3/12/2024 at 1:46 PM, Bjørn Edvard Torbo said:

Try to deactivate the W1G in FontBook and see what happens. 

$ FontBook
sh: 1: FontBook: not found
$ fontbook
sh: 2: fontbook: not found
$ font-book
sh: 3: font-book: not found
$ Font-Book
sh: 1: Font-Book: not found
$

 

Depending on your operating system, the font management utility may be called something else. FontBook is built into the MacOS system. With FontBase (open source), you should be able to activate/deactivate fonts on Mac, Windows and Linux systems easily.