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