Works for RTL8168, RTL8111, RTL8169, RTL8101, original project page is http://sourceforge.net/projects/realtekr1000/ and was an open source community project, enhancements done by Psystar and re-released under a Psystar license.

New website available here: http://store.psystar.com/opensource/r1000, links are known to not always work, therefore the source and a pre-built kext (compiled by yours truly) are attached.