There are a number of very large genealogical datasets on the internet, FamilySearch and Ancestry.com being the two largest and well known.
GenCircles, though less well-known, is another biggie. I'm not sure just how big, but by my calculations, there are more than 12 million individuals listed just under the letter "A". It's pretty big.
A visit to the homepage has the usual, familiar-looking search boxes: enter a first name, last name, year of birth or death, and so on. Why bother?, you ask. What makes GenCircles different?
Infuriatingly, the site doesn't tell you! Nowhere is there any description of what GenCircles is, what makes it stand out from other data sources, and why you might want to spend any time there. Their "About GenCircles" page is singularly uninformative. I can't believe that people still design websites this way. Why, oh why, oh why?
Still, I've come across records on GenCircles that haven't shown up in other databases, so it seems worth a search right there. Any source that can connect genealogists with new leads on family history is one to explore, especially when it's easy and quick to use.
If you work with GEDCOM files (standardized genealogical files), you can upload them to GenCircles and their special SmartMatching software will look through millions of files to try and match your closest ancestors. (However, see the insightful comment on some drawbacks of GenCircles added by reader, Dee D'Errico....Thanks, Dee. )
As with other datasets, GenCircles makes it possible for those with an interest in the same family history to contact one another, and share additional information.
These types of one-on-one communications can sometimes reveal more than a host of data sources ever will.
Visit the main page of Free Genealogy Tools for more, umm, free genealogical tools.
And don't forget to also check for your family history at Ancestry.com and NewspaperArchive.com. These are subscription databases, but they are among the most powerful research tools available for looking into family roots.