Users searching for a "Fluendo download" today will often find dead links or legacy pages. Modern Linux distributions have evolved, and the need for a specific proprietary player like Fluendo has diminished.
After purchase, you will receive a .deb package specifically built for Debian-based systems like Ubuntu.
Fluendo may prompt you to set a region code (1 for USA/Canada, 2 for Europe/Japan, etc.). You can change this up to 5 times.
When it was available, Fluendo provided a "legally unquestionable" way to play DVDs by including licensed decryption technology, avoiding the need for open-source workarounds that are restricted in some jurisdictions.
If you prefer a free (but less legal in some countries) alternative, look up libdvd-pkg and libdvdcss2 from the VideoLAN repository. However, for a experience, Fluendo is the top choice.