LibreOffice is what the OpenOffice developers spun off when Oracle took OpenOffice back from the opensource community. Oracle gave OpenOffice to Apache last year, but it still has all sorts of licensing issues, since it's sorta-kinda under both GNU and the Apache licensing models, and they aren't very compatible.
The Document Foundation forked the last opensource version of OO and created LibreOffice as opensource, and I agree, they've done really good things with it.