Oracle refused full open-source and crap for OpenOffice so all the key people forked off into LibreOffice. It's essentially the newer versions of OpenOffice which is likely dead as a project.
To respond to actual topic, outside of MSE, Malwarebytes/SpyBot/SpywareBlaster are generally alright things to have around, latter two for passive protections. None of them really suck up RAM like the good ol days though. There's also PeerBlock if you're paranoid. (Or if they're out to get you.)