Gramps - Research, organize and share your family tree with Gramps genealogy software.
Agelong Tree - Offline family tree software for Windows and Mac
WikiTree.com - The WikiTree community is growing a free worldwide family tree. The site is 100% free.
MyHeritage - MyHeritage is a family-oriented social network service and genealogy website.
My Family Tree - My Family Tree is a genealogy product for all keen family historians.
FamilySearch.org - Free Family History, Family Tree, and Genealogy Records and Resources from Around the World