Gramps, the open source genealogy program
Gramps is a genealogy program for Linux, Windows, Mac, and FreeBSD that allows you to easily build and keep track of your family tree. It supports the GEDCOM standard, allows fine grained privacy controls and can generate many different types of reports (descendant trees, graphs, connection diagrams, ....)
PhpGedView is a revolutionary genealogy program which allows you to view and edit your genealogy on your website. It has full privacy functions, can import from GEDCOM files, and supports multimedia. It also simplifies family collaboration.
GDBI is a genealogy program integrator. It includes an editor and the lifelines report language. It interfaces to multiple GEDCOM databases and is most popular as a PhpGedView client. At the core is a Java API to simplify adding databases and editors.