Don't bother, I tried with a disposable email address and they make you subscribe to a mailing list before sending you the download link. When you do eventually get it, it's a 3 page puff marketing PDF.

I converted it to TXT and pulled out the only bit of interest here:

                  Collabora Office                              Collabora Office Classic
                  Fresh, modern UX                                Classic, established UX
  Javascript & CSS UI to match Collabora Online                    VCL-based classic UI
       Simpler settings / streamlined defaults           Very extensive options, menus & dialogs
                       No Java                       Java used for some features/wizards/DB drivers
                 No built-in Base app                                Includes Base UI
                     Runs macros                    Full macro editor & advanced BASIC/Python/UNO
      Modern web tech (Canvas, WebGL, CSS)                         Custom toolkit (VCL)
     Fast to iterate (edit JS, fewer recompiles)      Core/C++ changes typically require recompiles
   Initial release – Enterprise Support is coming            Long term Enterprise Supported
       Quick Start Guides and video tutorials                  Extensive manuals & books

But how will we spam you if you don't give us email?

Even funnier when you try that from the "freedom" whitepage download https://www.collaboraonline.com/case-studies/opendesk/

If you don't give an email address, it doesn't even prompt you to ttry again. It just bugs out and redirects to a home page with a broken URL attempting to inject HTML from client side.

That's strange because the only reason for a user to use OpenOffice/Collabra is because they don't want to deal with an annoying company that makes a far superior product. If the inferior product is also run by an annoying company, why bother?