Genealogy programs such as RootsMagic and Family Tree Maker store data in a format unique to that software. That means you can’t open your uncle’s .RM file (RootsMagic’s native format) in your Family Tree Maker program. You can quickly see the sharing limitations this can create for genealogists who want to collaborate. The GEDCOM file format was created to solve this problem.
GEDCOM is an acronym for Genealogical Data Communications. Files formatted this way can be read by almost any Windows or Mac genealogy software. This means you can export your Family Tree Maker file as a GEDCOM and a friend can import that same GEDCOM into her Legacy Family Tree or any other genealogical software.
You can send a GEDCOM file as an email attachment, burn it to CD and mail it, or upload it to a website. GEDCOMs do have a few limitations: They’re text files, so they don’t include any images, audio or video that you’ve attached in your software program. Sometimes details “lost” when you’re exporting or importing a file. Not all genealogy programs import GEDCOMs’ source information the same way. Genealogy organizations are working on new ways to share files, but for now, the GEDCOM is the most widely accepted method.
Each program creates a GEDCOM a little differently, but in general, you’ll open your family file in your genealogy software, then select Export from your File menu. You may be asked whether you want to export the entire file or only part of it.