These are motion picture films like Kodak's Double-X 5222.

Orwo UN 54 is a 100 ASA film, Orwo N74 is rated at 400. They are both traditional grain films and somewhat descendants of films from former East Germany, made by a company named Filmotec (formerly known as Orwo Filmfabrik). They are not available in cartridges, only in 35mm rolls, and they are quite cheap.

Did any of you ever use these films and process them in modern developers? I would very much like to see some examples...

There are the specifications: