It wasn't frozen, Collabora were the ones doing the work and so they have largely hosted and developed LibreOffice Online.
(same thought here; just didn't want to sound harsh)
The idea of LOOL (LibreOffice OnLine) is to be an embeddable component; we have used it before on a Moodle site. And this is the same for COOL (Collabora Office OnLine), which is used by Nextcloud Office (as components called COOLWSD, and LOKit).