Gramps - Research, organize and share your family tree with Gramps genealogy software.
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.
Ancestry - Discover your family history and start your family tree.
FamilySearch.org - Free Family History, Family Tree, and Genealogy Records and Resources from Around the World
webtrees - webtrees - the web based Family History Software - is based on the popular PhpGedView ('PGV') application.