Gnuology is described as "a wiki for genealogy." It imports a GEDCOM file and then allows many people to view and edit the data through their favorite web browser. The edits can be saved and then become instantly viewable to everyone else.
Gnuology is not a program that runs on your desktop or laptop PC; it is designed to be installed on a web server. It works on Windows Server and on many flavors of UNIX and Linux. Users then can access the data on the Internet, assuming the administrators have granted user names and passwords.
The software is being developed by developed by Mike Gashler and Dr. Doran Wilde. They have released it as open source software. That is, the program is free and you can even modify its operation if you are a programmer. (Gnuology is written in C++.)
The Gnuology project presently is in alpha development stage, not beta test. In other words, not all the code has been written yet and you certainly can expect to find bugs, perhaps major bugs. I also found the documentation to be virtually non-existent.
This project isn't ready for "prime time" yet but it certainly looks interesting. I'll skip it for now and would recommend you do the same, unless you are an experienced C++ programmer who would like to contribute some programming efforts to the project. However, if this project continues to development, Gnuology could become a very useful and interesting program.
If you would like to try Gunology on your web server, take a look at http://sourceforge.net/projects/gnuology.