http://aminet.net/package/util/dopus/DOpus4-Version12.lha
http://dopus.free.fr/files/CU_DirectoryOpus.zip
OS 3.0+
http://dopus.free.fr/files/DOpus416JRbin.lha
https://sourceforge.net/projects/dopus5allamigas/
https://sourceforge.net/projects/dopus5allamigas/files/Dopus5.82/
https://sourceforge.net/projects/dopus5allamigas/files/Dopus5.90/
http://aminet.net/package/util/dopus/Dopus5_91_os3