Open Source #family-tree Projects
Discover open source software tagged with family-tree.
Gramps
Open source desktop genealogy program for building and exploring detailed family trees with full local data control.
Alternative to: 
Family Tree Maker
Family Tree Maker
webtrees
Self-hostable web-based genealogy application that turns GEDCOM files into collaborative family tree websites.
Alternative to: 
Ancestry.com
Ancestry.com