[ktizo]

For the past year LibreOffice has been the one worth following because OpenOffice was put on hold after the Sun acquisition, then shifted to Apache where it has now been resurrected.

My view would be that it is well worth seeing what Apache do with this, however Libre currently seems to have more active development (although I could be completely wrong as I don't know what sort of resources Apache have been throwing at this).

Given they are both free, it would seem like a good idea to pick one for day to day use, but follow both closely, much like the situation with the browser wars.