Originally Sun sponsored openoffice and it was a great alternative to MS Office. When Oracle bought Sun many of the top developers branched off and started libreoffice, following in the footsteps as an "open" ie. not controlled by a corporation project. At that point they both were based on the same code. Now libreoffice seems to be the most dynamic and up to date version. Now Apache's in the mix and while they've made some great software, I'm skeptical and trust libreoffice more.