Gramps - helps you track your family tree
Gramps is a program for genealogical research. It is an extremely flexible program that meets the needs of both the amateur genealogist and the serious genealogical researcher. Allows you to store, edit, and research genealogical data.
Has the ability to import GEDCOM files exported from many proprietary genealogy programs and can generate a large number of reports in many popular formats. This allows any piece of information to be entered directly into Gramps and any event to be manipulated across the entire database (in any order), helping the user research, analyze and find connections with the ability to fill gaps in relationships.