The WikiTree webmaster is Chris Whitten, the creator of WikiAnswers. The web server software used is based on Mediawiki, the same software used to host Wikipedia.org. All genealogy content is edited and owned by contributors.
WikiTree claims that the mission is to create a rich worldwide family tree resource by striking the perfect balance between collaboration and privacy. Indeed, you can find many online sites for publishing your genealogy information but not all of them provide privacy controls.
WikiTree incorporates a "Trusted List" system to customize the access you give to distant relatives. Each person, place, or thing listed in WikiTree has its own Trusted List. Similar to "Friends Lists" on social networking sites, each user on a Trusted List has to be individually approved by the person who uploaded the information. Trusted Lists for non-living or inactive people, places or things are controlled by the users already on the Trusted List. Most information about living people and their nuclear relatives is protected so that you need to be on the Trusted List just to see it.
The result is a tightly controlled database for publishing information. However, the downside is that much of the information remains hidden from newcomers who discover the site and wish to peruse the information. I searched for various surnames and could see many names listed. For individuals born in the 1600s through 1800s, I usually could see full name, names of family members, date and place of birth/marriage/death, and more. Of course, all information is as good as the accuracy of the person contributing the data. However, clicking on any of the names of anyone who is probably still living displayed a page providing only that person's name.
To add information to WikiTree or to view much of the information entered by others, you must create a free user name and password. You can add information manually from the web browser, one person at a time, or you can import a GEDCOM file created by most any modern Windows, Macintosh, or Linux genealogy program. As such, you could contribute information about thousands of people with one GEDCOM import. You can also add pictures as well, although not from a GEDCOM file.
Each person is the subject of a separate wiki page on WikiTree.com. Assuming you have access to the information available, you can add parents, spouses, siblings, or children to any person already in the database. You can aso add source citations and text information (biographies) for any of the people in the wiki database.
You can invite others to join your "Trusted List" by suggesting they visit the WikiTree.com home page. Someone who has been invited to join WikiTree but hasn't become an active user yet is "Pending Person". This distinguishes them from a "Passive Person" who may be a long-dead ancestor.
To explain it in another way: a person's record without an e-mail address is considered to be a Passive Person. When you invite someone to join by adding an e-mail address for them, their record is considered Pending. When the person accepts the invitation and creates their own password they "take possession" of the person record and it becomes Active.
Once the person takes possession of his or her own person page, he or she then controls the Trusted List for that page. This way you can collaborate and share information without giving access to strangers for all your family members' information.
WikiTree also supports printing of the information stored within the wiki. One limitation is that you can only print five generations at a time. Five generations was chosen because it would be hard to fit more than that on one sheet of paper. You can learn more about WikiTree printing capabilities at http://www.wikitree.com/printable/family-tree-diagram.html
WikiTree is free. Quoting from the WikiTree.com web site: "We have made a commitment that WikiTree will always be free for its users. Nobody will ever pay to access information here." The web site also states, "The small expenses of running the server are covered by advertising on public pages. "
The day that I visited WikiTree, the site contained 204,728 profiles of individuals.
WikiTree.com strikes me as a great idea but the site faces stiff competition. Other web sites already have a head start on WikiTree and already have huge databases, offering various degrees of control for privacy of information. Even free sites, including FamilySearch.org and WeRelate.org, already have established databases containing information about millions of individuals contributed by genealogists. It should be interesting to watch the struggles of these sites over the next few years to see which will be the more popular services.
You can learn more about WikiTree or even create a free user account and contribute your own information at http://www.wikitree.com